But they are useful and completely valid ways of dealing with the problem.

It is not the end of the world if I have to click am extra once or twice to change the language. Hell most websites have much harder processes just to reject cookies.

Personally I would rather err on the side of slightly extra work the odd time I'm not on a website not in my native language than have an extra bit of information that can be used to track me.

Again take a look at the Gemini protocol, its a perfectly fine browsing experience without all the cruft.

First language in Accept-Language header that server also support

Some widely spoken language I imagine, Chinese, Spanish, English I don't care. Since .com is intended for commercial use, the language of the companies biggest market makes sense here as well.

You're also forgetting that the likes of google.ru, google.nl and google.every_other_country_code exist.

Also there are plently of websites the have language selection in the site that overrides that header, look at Wikipedia.

There are plently of sites in non english languages that cater to non English speakers only, not every site has or needs 10 different translations.

At this point we also have translation engines in the browser so for pages in languages you don't know, that you absolutely need to access, you can use it to understand the page to a decent level and/or be able to navigate to a version in your language if available.