Most websites handle it just fine, for the advanced interface of Mastodon the screen could be even wider! For the rare website that doesn't handle 16:9 well I have this bookmarklet:

javascript:var%20b=document.documentElement;b.style.width='900px';b.style.marginLeft='auto';b.style.marginRight='auto';void(0)

I run everything maximized on my 32:9 and it's fine to me.

(I've never had overlapping windows in my life -- I find seeing more than one thing super distracting and it annoys me that this seems to be the default on Macs)

One of my monitors is 9:16 - I've rotated it 90°. It's terrific for reading PDF documents, web pages, a terminal, and the IDE.

The only thing it's not really good for is the email client, video, and pictures. For those I have another monitor in the standard landscape configuration.

I used to have a similar setup, but I replaced the dual head setup (24" 9:16 and 30" 16:9) with one ultrawide one.

I suppose just as wide 16:9 display would have been even nicer, but it's fine. There are some benefits in window placement in having just a single screen, even if window managers could work better for this use (e.g. have a "second screen" region where there are separate workspaces).

It's not.