I think many of the things you are surprised about on web pages such as Amazon or Google search results are due to accessibility.

Yet at the same time, you are advocating for keeping familiarity but want tab to skip entire parts of the web page.

I've long clung to Epiphany (the Gnome browser) simply because it did a bunch of things right (eg. back button works in a new tab opened with a link), but at some point gave it up because it was falling behind in other rudimentary features. Which is to say that you are sticking with Chrome because it does all the other stuff reasonably well, not because of that one pet peeve of yours.

And no browser is good in regards to memory management, because web pages are not keeping their memory use in check.

I presume some of these things are due to accessibility, but Amazon's site is near impossible to navigate even with 20/20 vision and all my faculties.

I'm not advocating for familiarity, but for predictability. It's not that interfaces shouldn't change, but that they should be predictable. If you're changing expected behavior (new tabs, tab, etc) you need the interface to reflect that. If there is something 99% of your users are doing in your page, there's a good chance that it's what should pull focus on page load.

Nothing works for all cases, but I think those are good guidelines.

You're right about memory management - sadly it's also the SPAs that I see download their entire dependency tree onto my system just to show me a few lines of text.