It was inevitable. Before the ink was even dry on the first reports in 2016 that Prince Harry was dating Suits star Meghan Markle, the Los Angeles native was already being hungrily compared to Diana, Princess of Wales.
Statuesque fashion lover? Tick. Avowed humanitarian? Of course. Mould-breaking woman intent on charting her own course? Bien sur.
Everyone and anyone who had even a passing acquaintance with the princess, from her one-time chef to her one-time bestie Sarah Ferguson, the Duchess of York, soon came out of the woodwork to speculate about whether Meghan would prove to be the natural heir to Diana's title of Queen of Hearts.
Because while the Queen and the rest of her musty lot might have watched the princess' trajectory from pale teenager to Versace-wearing Boudica with purse-lipped anger, the public adored her for it.
The world bore witness to her extraordinary transformation and we were beguiled time and again by her lusty commitment to making her royal platform count for something. She didn't just give a nice speech, sprout some platitudes and hope bad things in the world would become better.
No, she put on a pearl choker and went and smashed through feeble notions of propriety like a blow-dried Sherman tank, moving charitable mountains in Chanel midi-heels.
And not only Britain but the world unreservedly loved her for it.
Nearly five years on from those heady, innocent days when Meghan first appeared at Harry's side in her oversized white shirt, we are on the other side of the all-too-brief Sussex era and any notions of happily ever after have long since been dashed, it's still a question worth asking though.
Did Meghan fail to live up to Diana's example? Did the actress-turned-duchess pass the Diana test?
From the outset way back in 2017 when Harry and Meghan got engaged, it looked like she would naturally assume Diana's mantle as the passionate, tradition-bucking, renegade and that she, like the princess, would approach her royal career driven by compassion.
From her very first official engagement, Meghan put on a positively Diana-esque display of the sort of tactile, deeply human version of royal life that the Princess of Wales had pioneered.
It soon became abundantly clear that Meghan had every intention of channelling Diana's passionate, vocal advocacy for issues close to her heart and that stiff upper lips and polite silence were not going to be options.
Women the world over cheered – here was our princess. Finally, here was a member of the royal family who brought with her the values and ideals that resonated with contemporary women, not a nude pair of pantyhose in sight.
But we all know how this story ends – in anger, hurt and duelling PR camps – and with the monarchy just having barely endured the convulsions triggered by the Sussexes' defection.
As the dust continues to settle post-Megxit though, one thing has come into focus – Meghan, no matter how hard she worked, no matter how much she tried, no matter how many hugs she dispensed and pensioners she charmed, she never really came close to winning the title of Queen of Hearts.
And part of the reason for that is that the public love Diana basked in was a direct result of how much definite, quantifiable good she did.
Looking back at the 20-months that the former actress was a working member of the royal family, the question is, what did she actually, tangible change, aside from courtiers' gin consumption?
In hindsight, Meghan's work, as hard as it was, did not fundamentally move the dial on any of her causes.
In other ways, the Duchess of Sussex had an indelible impact. Her tenure has forced British society and the media to take part in an unprecedented reckoning about race and the nation's treatment of the first woman of colour to marry into the royal house. (Lady Davina Windsor, 34th in line to the throne and the daughter of the Queen's cousin, the Duke of Gloucester, married Māori builder Gary Lewis in 2009.)
But what I'm talking about here is that Diana's activism and advocacy did long-term, demonstrable good, something that the Duchess of Sussex never quite achieved.
I'm not saying for a second that Meghan did not work extraordinarily hard. For heaven's sake, one of the earliest complaints about her was that she would email staff at 5am. Oh the temerity of having such unapologetic zeal and get up and go!
In fact the numbers paint a truly impressive picture.
She carried out 198 engagements while she was on the royal "clock" and undertook three overseas tours. During Meghan and Harry's South Pacific tour in 2018, she notched up 76 engagements (and 40 outfit changes) in 10 towns and cities in 16 days. Oh, and she did much of this while she was pregnant and suffering serious mental health issues.
Where Meghan and Diana's paths veer dramatically apart is when it comes to being able to point out to how one woman changed things for the better in a concrete way and the other didn't.
Diana seismically, and I don't use that term loosely, changed the perception of Aids patients in the '80s at a time when the stigma around the disease was extreme. In 1987, when people still believed that you could catch the virus via touch, Diana opened the UK's first HIV/Aids unit in London and was photographed shaking hands with a patient without wearing gloves.
She intrinsically understood her own power and wielded it with precision and breathtaking savvy. Photos of her readily touching a man with the disease was nothing short of a revolutionary move.
It's so tragic that Meghan does not have quite the same resume of trailblazing work.
Impressive, clever, and impassioned? Hell yes. But paradigm-shifting force? Not really.
Sure, she helped put out a charity cookbook that has sold more than 130,000 copies, she guest edited an issue of Vogue, launched a clothing collection in support of the charity SmartWorks (of which she is patron), and made gender equality a cornerstone of her work – but she never truly changed the landscape.
This week, veteran biography and investigative journalist Tom Bower, who is currently working on a biography about Meghan, weighed in on the issue during a TV interview.
"Diana was famous for what she did," he said, pointing out that she "only became such a loved figure in Britain because she devoted herself so much to the poor, to the afflicted".
"Meghan doesn't realise that she hasn't done anything," he said. "She may be a philanthropist, she may be an activist, but I haven't seen results."
It is so tempting, and so poignant, to wonder what she might have achieved under the aegis of the royal family, if she and Harry had somehow stuck it out.
What will be fascinating and thrilling to watch in the years to come is what Meghan, via the couple's Archewell Foundation, will achieve. Given her tenacity and unimpeachable work ethic, I would bet she will not only meet but surpass the benchmark set by Diana and become an even more consequential humanitarian voice.
To put it simply, in the future I'd wager that the Duchess of Sussex will only become an even more potent force for good. It's just such a rotten shame for the royal family that she won't be doing any of it under the palace banner.
• Daniela Elser is a royal expert and a writer with more than 15 years' experience working with a number of Australia's leading media titles.