Politico/Morning Consult took polls before and after the debates, and nobody moved more than the margin of error.
Only four candidates moved at all, and all moves were statistically meaningless:
- Biden dropped from 33 to 32
- Warren increased from 13 to 15
- Harris dropped from 12 to 10
- Buttigieg increased from 5 to 6
So I guess you might fairly conclude: (1) if nobody won, that’s a win for Biden; (2) if nobody generated any excitement, that’s a win for Trump.