H3 hexagons by Uber solves a similar problem with better characteristics- when people talk locations, they typically also want to get distances between locations. Because h3 is hexagonal (pretty much) it has a nice property that all immediate neighbors are the same distance away, which makes traversal and distance easier. This is not the case with squares.
Yep, the basic web UI is a bit weird. However, if you go into preferences and enable the "Advanced web interface" option, it turns into a cool, Tweetdeck-like interface with customizable columns.
The basic UI always surprises me whenever I open a new mastodon account, and then I always forget about it. :)
This is actually almost exactly what Snapchat stories - now also on Instagram and Facebook - achieve. You can click through your friend’s updates, reply as you want, and when you’ve seen everyone you’re out of content until someone posts again. I kinda like using these apps in this way, because it’s still cool to see what people are up to, usually more genuine, and harder to get sucked down the scroll.