A huge part of that has to be that in modern day society we're constantly bombarded with those one-in-a-million stories that are presented as if they're the norm. And don't get me started on things like sports stars with insanely rare genetic gifts who then write books that say "And I knew it would just take hard work to make my dreams would come true" - sure, you worked hard, but so did a bajillion other folks who didn't win the genetic lottery that you've never heard of. And in many places, like the US, it's also widely preached and believed that the US is a meritocracy, and that anyone can achieve greatness if they work hard enough. I don't really want to get into the "meritocracy" debate but I hope everyone can at least acknowledge that luck is a huge component of any exceptional success.

Before global media, for the most part if you were comparing yourself to other people it was largely comparing against your friends, family and community. Sure, there may have been that one outsized success, but it still wasn't presented as the norm - you knew all the other friends and family that just had average lives. And for most of human history where social ranking was explicitly classed based, it's not like if you were a peasant you would think "Darn, if I only worked harder I could be a noble".

If you want to feel "less hard on yourself", I highly recommend disconnecting from digital media. It's hard for our human brains to deal with the constant onslaught of stars/celebrities/moguls/exceptions and understand how rare those examples truly are.