Regular users use a browser extension like ublock or Adblock to block ads. Not improving DNS security for the sake of a few users obscure Adblock mechanism would be pretty silly.

Regular users also use Norton, McAfee, and other vendor Internet security suites. Some of those will also use the hosts file.

OK, but software like that can easily include an internal DOH proxy (or just turn off DOH in Firefox).

And what market share do they have? None of my non-techie relatives or friends who've asked me to look at their machines run that kind of software.

Only the use case with the largest market share matters?

That kind of thinking, really irks me.

No, I don't think like that.

It does bother me when Firefox introduces a feature which covers up a huge hole in TLS, and they get a large number of complaints on HN.

Of course it gets large number of complains, when it creates more problems than it solves, and it is papered over "but mainstream users do not need that".

Mainstream users do not need most software ever made.

Did you see someone in this discussion suggesting "but mainstream users do not need that"? I just checked again and I don't see anyone making that suggestion.

It is paraphrased. The argument is, that it improves things for the mythical naive mainstream user, and for where it break things, well they are minority anyway.

I didn't see anyone making that argument, either. Are you trying to summarize what I said? If so, that's not what I said. I'd love to have a discussion about these issues, but it's not going to happen if everyone's talking past each other, plus random downvotes.