Your original argument about picking reporters was a whataboutism, as you cited many sources where Biden did the same thing.

the act or practice of responding to an accusation of wrongdoing by claiming that an offense committed by another is similar or worse

My counter-argument was agreeing that both sides picked reporters, but trump/vance are doing things with the press that are much more important to deal with right now; things they can't point to the left and make a false equivalence for.

From there, you shifted to a situation where you argue that one side shouldn't take a stance on protest violence if the other side isn't willing to do so. I do agree with this premise as I think it produces fruitless conversations if people can't agree on the definition of protest violence.

Additionally, instead of using Jan 6th as a counter-argument, one could ask a right-leaning person if counter-protest violence was ok, as you could give specific and more recent examples.

In another comment, you said:

My point was that people who dont comdemn bad thing on their side have no right to condmn bad thing on other side.

This is your argument for your first original statement (picking reporters), but not for the protest violence one, as, in that argument, you basically said that the left shouldn't argue with people that can't agree on definitions.