I consistently hear people on YouTube complain that the subscribe button doesn’t do anything for viewers, now that channel notifications are controlled by the bell. But it does do something: it puts the videos from that channel in your subscription feed, which is readily accessible on all versions of YouTube. So why do people act like it doesn’t exist? I think it’s super convenient, especially if you’re subscribed to a ton of channels and don’t want your notifications feed flooded with new videos.
I’ve heard good things about Nextcloud News but never used it myself. The most important thing is to pick one and get started. Once you have some experience reading feeds you will have a better idea what you are looking for and re-evaluate the options. With OPML import and export being widely supported switching readers is easy.