This is good advice. I love Twitter, and find you need to be ruthless in unfollowing anyone who ruins the experience for you. Unlike Facebook, there usually aren't social / real-world consequences for unfollowing someone on Twitter.
For people who are noisy but you still want to follow, shuffle them off into a Twitter list you check occasionally. I love @SwiftOnSecurity, but she's too noisy/frequent for my main feed, so I don't follow her and only include her in my Infosec list (that also includes @troyhunt and @tqbf).
You'll probably enjoy Twitter a lot more if you use 3rd Party clients like Tweetbot (Mac / iPhone) and Fenix (Android). Zero ads and more flexibility with features like Mute Filters (eg muting specific hashtags as well as specific users). The official Twitter experience is terrible.
Don't feel obligated to follow friends. This is often the fastest way to ruin your Twitter experience.