I think the better option is to update the app until it starts getting worse, then switch to something better. If I was depending on a particular app to a point where losing feature X or Y would be any kind of disaster, I'd be actively looking for a different solution.

If it is an app you care about then you better go read the reviews before updating because you cannot roll back.

Sure you can, if you have a backup of the ipa file on your computer.

I haven't connected my phone to my computer for years so that won't really work for me, but yeah you could go that way.

Technically, you don't need to connect your phone to the computer. It will do it w/o your intervention. I backup/sync all devices in the family to one computer over Wi-Fi.

Can you roll back to a previous version of an app using iCloud after you update? I don't think so.

How does iCloud comes into this picture?

Grandparent suggested using iTunes on computer for ipa backups. I've added that you don't need to connect your phone to that computer.