If you compare the pg essays from 2000-2010 to 2010-now, there's a very noticeable shift in tone on this exact topic, even moreso if you zoom out of pg and consider YC messaging then and now.
Tons of old pg essays sound straight from something like Indie Hackers or Microconf with their "avoid raising VC money" angle. He even literally predicts the death of VC in web SaaS, saying "investors aren't worth the trouble": http://www.paulgraham.com/divergence.html .
His YC cofounder Jessica Livingston wrote a book "Founders at Work" and about half the founders in the book are bootstrappers (DHH, Joel Spolosky, Craigslist). The other half are mostly founders recounting horror stories of interacting with VCs.
Compare that to modern YC where there are videos where they say _everyone_ should consider applying to YC with the _only_ exception being people that want to bootstrap. Modern Startup School says: "Without startup funding the vast majority of startups will die." (https://www.ycombinator.com/library/4A-a-guide-to-seed-fundr...).
There's something very important to note which is that YC did not change the deal from 125k for 7% to 500k for 7%. It's still 125k for 7% plus 375k worth of equity on your next raise. Which only makes sense if there is a next raise. So obviously they discourage bootstrapping since their whole model has been built around you raising at least one more round after YC.
Seems a pretty simple case of "follow the incentives." YC basically became more of a traditional VC over time. And I think pg was still closer to a founder in the early 2000s, from a founder perspective, it's more of a set of tradeoffs whether you should bootstrap or seek VC. But from a VC's perspective, obviously they want you to seek VC since they can't get involved if you bootstrap and bootstrapped startups won't get the outsized returns they need.
My opinion is, pg is a smart guy, there's still a ton of wisdom to learn from in his essays, but as with every other person on the planet, consider their motivation and incentives for telling you what they're telling you.