I’m not arguing that it makes anything slightly worse. I’m arguing that it doesn’t make it worse at all. Of course, this is subjective.

I think this change is overall more consistent than previous Firefox versions (menus). I also think it removes clutter and looks simpler, cleaner, and less distracting.

But were you actually distracted by the clutter before?

Less clutter.

Isn't each tab clear from the fact that it starts with an icon?

No. It only works if you're so familiar with the previous UI than your pattern recognition kicks in. Someone who sees this for the first time will have no idea what it means. It's inaccessible to the novice.

Also, tabs without a favicon don't start with an icon at all.

> It's inaccessible to the novice.

It doesn't seem to be the novice people speaking up against it? Or are they all acting in defence of novices they don't know?

> But why do you even have to start with

To address a common complaint? Frankly, I have no trouble at all and I think most people are complaining due to change - a tale of software developing old as time

I mean, if lots of people complain - and keep complaining, that's usually a sign the complaint has some substance.