I have the newer remote and it does not work for me either. If the touchscreen is obsolete, then why would they have a TV remote on your iPhone? I am still updating my Apple TV, even though I have automatic updates enabled.
I had one of those remotes and it fell and shattered. It caused my child to get their thumb cut by the broken shards of glass on the surface of the remote. This hazard or another similar issue is more likely than not to be the reason why they changed their remote design.
I will update the community if I can resolve the issue myself. I did see a lot of people have been googling “how to cancel my paramount + subscription.” I am not sure why people are canceling their subscriptions but it could be because the app doesn't work and is worthless without this issue being resolved. I will be asking Apple for a prorated refund for the time I couldn't use their paramount + app.