I agree completely and have submitted feedback on this very issue. (Though, to be clear, that's a macOS issue, and this article is about iOS.)Is my vision really so poor that I'm the only one who's biggest 'pain point' is actually simply finding the active tab when the web page presented in the tab has a black background (i.e. the majority if you run in "Dark" mode)? I have to set the screen to maximum brightness to just barely make it out! Attaching screenshot.
I was hoping this beta made things better. It did a little bit - by adding some sort of thick line(??) under the non-active tabs - but those are also nearly impossible to make out in the above case.