I would like to be able to choose how much I want to see of the topics I like. What platform offers something similar to Bluesky customizable feeds but in the fediverse?
I'd say in general this would be Bonfire but it's still in active development and not yet ready to run stable as a public instance.
I mean, I consider Mastodon pretty "customizable" in the sense that you state. It's easy to follow individual hashtags surrounding specific topics, groups that people use to post about a specific topic or individual users. My home timeline is pretty much all topics I'm interested in due to who and what I follow.
Similar to Lemmy really. Your subscribed feed should be exclusively topics that interest you from the communities you subscribe to.
Friendica has a group, real groupe! And they can be available (Misskey groups only for Misskey not for outside!) Compatible with Diaspora can communicate and other things that can propose Misskey.