If you block somebody then it prohibits you from commenting on any of their questions or answers also.
And if you block somebody they're questions and answers should become invisible to you you won't be able to see their questions or their answers or comment on their questions and answers if you block them. That goes for anybody fair is fair.
I'm not sure what your suggestion is. Blocking is an anti-stalking measure. It stops people from answering your question and from commenting on your answers.
there is another suggestion asking for more clarity as to which questions you are blocked from.
Not being able to see someones question could stop you from reporting violations
Not being able to see someones answers could cause you to post an identical answer, which would be a violation of the guidelines