>Having this whole functionality is entirely preferential, so?
Sure. No feature will please everyone and some may actively oppose a few individuals
https://xkcd.com/1172/
That's why options to customize the experience is the best of both worlds. But focusing on solid defaults and then opening up with options seems to make sense.
>>That's a bad, though universal (can say exactly the same thing on 100th release) excuse
Okay. This feature had 2 updates thus far. As the kids say, "let them cook". I sure prefer an iterative release over even more delay on such a widely requested feature
> want zero waste
You need to define "waste" first. What does "zero waste" even mean in terms of UI real estate? These paradigms vary from culture to culture (e.g. Check out how utterly dense Japanese website UI is), and then person to person.
> You can start by measuring actual width instead of making up tiny numbers.
And you don't think the designers and engineers at Mozilla did this and simply interpret a different benchmark from you? I'm sure like the rest of the base UI the scaling is responsive and the size chosen balanced visual ease of perception, average user precision, and compactness.
>And then go on estimate the % of users who have more tabs that fit the screen width - that's the number is anyones no waste will be helping
Given reports in this comment section of people with 2000+ tabs and people apprehensive about more than a few tabs open, I hope you can imagine the challenge trying to accommodate such a range.
I also imagine the designers did that work already. If it fits what some quick research I did suggests, the average tab count maintained is on the lower side.