I'm not a fan of this trope either, especially if the story, when starting out, emphasized how underdog the MC was for not coming from a certain heritage or having certain powers. Or how hard work and determination overcomes heritage (ahem, NARUTO). But I do understand it's a form of escapism and we've all fantasized at some point in our lives "what if our family was secretly mega-rich?"
I'd actually say Harry Potter doesn't fit this trope because even from the get-go he was a special prophesized child and it was clear that him surviving Voldemort's killer juice squirt was very special. With Rey —... well, the whole trilogy is a mess
Long-running stories often come into this problem, I think. Especially in stories involving fighting powerful magical villains. Creators, in order to meet the rising power levels, end up giving their MC some magical heritage powers to be able to defeat the ever-more-powerful villains. The "nature vs nurture" issue is swept to the side, as "nature (heritage)" always wins in these stories.
Side ramble while I'm on this topic — I am a Kingdom Hearts fan. Sora, the MC, so far has the story of being a normal kid with a heart of gold, who gets his strength from friends and connecting with others.
Canonically Sora wasn't even the first choice for his Keyblade — his Keyblade was originally his friend Riku's before the Keyblade decided to change its owner. And the games repeatedly state that it's his kind heart and his friends that is the source of his power. Without his friends and that connection, he stumbles and falters.
Anyway, I'd hate it so much if later down the line, he was revealed to be a reincarnation of a god or something. Please let Sora stay a normal kid who got to where he is because of his kind heart and with the power of friendship Let his kind heart be his special thing, not some magical heritage.