I hate that my first thought upon muting someone is "I should also subtoot them." No, me. You should not. Remove them from your timeline and move on with your life. There is no need to do something so toxic.
(This, ofc, isn't to say all subtoots are toxic. But sometimes, it's just uncalled for. Sometimes, it's okay to just mute and move on. You don't have to call out every little thing.)