I agree with the overall point, but I want to talk about this:
Finn in TFA is a quite a bit closer to being Han, with he and Rey both splitting some traits of all three OT cast mains.
Poe is a minor character more akin to Wedge in TFA.
And I think that two things screwed that up: the decision to make Rey not a Skywalker, and systemic racism that Finn suffers from and that Kylo (and maybe to some extent Poe) enjoy.
Finn in TFA has a hell of a lot of Han Solo parallels, and gets quite a few rather on the nose interactions with Han that seem to make the parallel a lot clearer. He’s given a role requiring a charismatic mix of humor and drama complete with awkward reactions with a bit of false bravado in them (“We’re all fine here, now, we’re fine... how are you?” is a lot like “The Resistance?...Obviously. Yeah. I’m with the Resistance. I’m with the Resistance.”) that nonetheless culminates in them having a dramatic confrontation with the main hero where they’re confronted for their more selfish flaws while admitting they care about each other, then they both have a “changed my mind, kid” moment in coming back to rescue the hero and save them when confronted by the main villain (Han protecting Luke with the Falcon is quick and a lot flashier than Finn holding off and tagging Kylo while Rey recovers from being thrown into a tree, but I’d argue Finn’s is more dramatic in terms of character arc.) Han also gets two scenes that make it clear some of the paraellles between himself and Finn are likely intentional (one of which I’ll get back to in a bit.)
And rather importantly, though admittedly subjectively and speculatively...
...I think that TFA only works out the way it did if Abrams and Kasdan wrote the script while working under the “soft” assumption (because Abrams hated planning ahead and LFL was against planning ahead entirely) that Rey was a Skywalker of some kind... and that Finn was her most clear and immediate romance option. The sheer focus and drive that Abrams had in trying to make sure that Rey and Finn’s chemistry and bind was as strong as it could be in TFA, even including major changes in reshoots to capture the actors’ natural chemistry, the way the confession scene is directed, the way the film outright admits Finn is attracted to Rey and gives her a Leia-like brusqueness towards him early on before he earns her at least platonic love...
...And the specific decision to feature a short, quick scene where Han, the OT’s romantic male lead, teases Finn with a parallel about how “Women always find out the truth. Always!”....
...All that feels like fairly specific set-ups for Finn as the romantic male lead with Rey. And to be honest, if that was the case, than I’d say all Finn really needed was a win over the stun baton-carrying stormtrooper and a few less jokes elsewhere, and he’d be a perfect counterpart to Han with a dynamic new origin story and potential elsewhere.
And then TLJ, with the introduction of Rose and hard line stance that Rey and Finn won’t share any dialogue and the way that LFL themselves seem to be the most overt pushers of the Reylo story (there’s some evidence they may have ordered it in TROS) - all that feels like the sadly predictable consequences of LFL allowing Johnson to denounce Rey Skywalker as “too predictable” and then automatically assuming that Kylo had to be her romantic option both because he was now the only Skywalker, and because for some reason they just thought a monster who’s white makes more sense as a romantic lead than a heroic black guy.
So yeah, to some extent I’m accusing LFL of both accidental systemic racism and spiteful “revenge ‘shipping tactics” to try and make Finn a “Ron the Janitor Muggle” while trying to make Kylo “Draco in Leather Pants.”