It would've been so nice if the EU had required there be an automated way to choose Accept All and Only Necessary options. They could've even reused the existing DNT header!

A Berlin court ruled that DNT counts as an opt out. Linkedin was the defendant that lost, but it is a precedent. There are also talks of outright banning targeted advertising in its entirety and only allowing other forms such as contextual ads.

What would be even nicer if companies just respected DNT header without any govs involvement, right?

Yeah, it was basically DNT except with teeth, would've made sense.

Or auto-reject.

Tangential, does anybody know a working cookie blocker extension for iOS Safari?

there is: stardust cookie cutter

But it's an extension, if I understand correctly.