The problem with this strategy is you can’t discover new content so easily. They should just let you filter subs from popular, not have you create some cultivated set of subs.
You can do this in the browser extension Reddit Enhancement Suite. It allows me to block the subs I want so that browsing All or Popular become good for sometimes finding new subs
There's a way to view "all," (I think it's built-in) and then write a blacklist. Looking at my list, I am mostly filtering out subreddits for specific video games and TV shows I don't watch.
Sync for reddit allows you to blacklist subs from r/all