And if you click past it to remain on the web version, you're presented with truncated lists ("Download App to read the rest!") or a slew of missing features.

I have an old Instagram account that I created over 10 years ago. At the time, I used it for the photo filters. Never cared about the social networking aspect. Just a month ago I logged into it for the first time in forever, and realized I wanted to delete those old posts. Guess what you can't do from the website? Yeah, delete posts. Need the app for that!

Not surprising. Facebook has very strict rate-limiting for deletion of posts, unfollowing of friends, leaving communities, and anything else that can potentially reduce your "engagement". Disabling it on some platforms was just the next step.

I think it was just never implemented. The web page is fairly basic compared to the app, and AFAIK always has been (although I never used it much and haven't had an account in quite a while). Quite a few products are actually app-only now, without even any sort of web or desktop version.

A few years ago I had trouble using the Dutch thuisbezorgd food service, I think it didn't allow me to change my address or something and just kept erroring out. I contacted support and they told me to use the app. I told them I don't have a smartphone. They said I was out of luck.