The only thing that really bothers me with the macOS 26 design update is the complete lack of contrast. Everything is white-on-white with super subtle shadows. You can't see what tab is selected in Safari, you can't see what is a button, etc. And it doesn't even look good - it just looks like something is broken, like a texture failed to load.

Tab styling across the board is terrible. I'm struggling to read inactive tab labels in Terminal.

I've used and loved macs for decades. This is the first time (maybe the second, if you count early Apple Music) that I've thought they've lost their way.