I imagine Trump’s hard-core base enjoyed seeing Trump do his thing, which in this case was to display dominance behavior as best he could over Biden and Wallace. He was in his game, but he didn’t knock Biden off his game. He did, however, keep Biden from gaining much momentum.
Still, I think this spectacle benefited Biden more than Trump. Trump, for all his noise, was playing defense, repeating all his Fox-tested base-pleasers, but not reaching out at ALL beyond that. I think Biden helped himself with both the undecideds AND the left wing of the party.