If you're really that worried about Let's Encrypt turning evil, you could stop having one when that actually happens. Or get a free one from many DNS providers. Or pay $5 for one. There is zero lock-in, and keeping traffic encrypted is a good thing.
Obviously that doesn't work for the web, but "TLS cert feudal lord" doesn't track for me at all.
But browsers are getting more and more restrictive about what they will allow their users to see. Right now technically ignorant people will be so confused and frightened by warnings they click away. That's okay, I don't care about those people. But for many it's a deal breaker. I give it about 3 years before the big corporate browsers stop allowing HTTP at all. Search engines already deprioritize HTTP and eventually they'll just delist. And it won't hurt their income one bit.
The number of sites that don't HTTP and just 304 to HTTPS is already frightening.
For a non-expert setting up a website from scratch, they can get the whole stack set up automatically and it won't make a difference to them. Especially since they're probably on shared hosting; shared hosting is much closer to the ideal of having the website be a folder of html than running an entire server.