The nice thing about Reddit is that content is strongly encouraged to group into subreddits making it easy to filter. My only problem is the opt-in model. I'd rather it be an opt-out model, show me r/all minus the blacklisted subreddits. They added a filter to r/all recently but it is limited to only 100 subreddits and is a pain to manage on mobile. So I wrote a script that periodically signs in as me and hides posts from subreddits I've blacklisted. It was initially getting the list from a google sheet but I've recently done something smarter. I have the script auto-subscribe to all new subreddits it sees on the front page and then monitor whether I stay subscribed. If it notices that I manually unsubscribed from a subreddit it takes that as a sign to blacklist that subreddit. It works amazingly.