The Old Reader supports 100 feeds on the free tier. And they have a nice list of apps that support syncing to your account:

https://www.theoldreader.com/en/apps/

Might work for you if you don’t syndicate many feeds.

I don’t know if calls work, but all the other stuff you mention does work.

Ah. Good point. I don’t think I’ve received calls. I don’t know if they would work

I have an old device in the closet and use the matrix bridge. The bridge bot kindly reminds me to turn on the phone every 12 days, but I think WA’s requirement is 15 days.

I do have to ask though: other than basic text chat, what else does WA offer these days?

For the record, I’m able to see videos, images and listen to audio. Haven’t received a poll yet. Is there anything more to it?