These also exist. Some clients integrate DVM feeds (Amethyst, Primal). Some clients let you view specific relays as a feed (jumble, coracle, yakihonne), and relays can be created for any topic. You can even run one, either on your own hardware or on hosted instance. relay.tools is a simple way to get started.

I'd advise to get a broader taste of what Nostr offers, you seem to be unaware of a lot of what already exists. You may need to find a better client.