A few years ago I bought an iPad (5th generation) with 32 GB and Wi-Fi (no cellular) to use as a cheap ($330 + $100+ for a Logitech cover/keyboard) guest machine for Kooma. Unfortunately due to various circumstances she never visited so I've been using it on and off as an additional screen.

First off, it was already kind of slow when I bought it. 3+ years later and it's still kind of slow but doesn't seem noticeably worse. If you're looking at web sites or doing other low animation stuff it's fine. Even watching videos is fine but moderate games are slow and I'd rather not play games on it anymore.

32 GB storage has been fine. I don't store much media on it and you can stream if you need to.

It still supports the last iOS versions, maybe without all the features.

Anyways I use it for:

Watching Paramount+ since that doesn't support picture-in-picture
Playing Star Trek Timelines when I'm also using my other iPad for Raid Shadow Legends
As a rarely used backup to my iPad Pro

Since I don't expect guests anymore I don't expect to replace this with another low-end iPad. Still, it does show that the low-end iPad is quite useful for a few years.