Absolutely underrated comment! Most websites use only 60% of the available screen width.

My first impression when they opened the sidebar was that that's what we were going to get.

The only thing really missing are disclosure triangles: https://imgur.com/a/6AkHI7d

A sidebar like that would serve tab-hoarders better than either the new or old tab bars, while coexisting with the new UI.

I would love that option too.

Edge does it.

Vivaldi is nice for this