So how effective was the Democrats TV only convention?

 So why do we hold political conventions.  Way back when, say John Kennedy's time, we chose the party's candidates at the convention.   Now we hold primary elections in every state to chose the party candidate, certainly more democratic, but it kinda took away the reason for conventions.  However, going to the national convention was so much fun for the delegates, that the parties still hold conventions, partly 'cause everyone has such a good time and partly hoping that TV coverage will win them votes.

   This year was a dry season, due to Corona virus, nobody went to the convention, it was all on TV.  So, did the Democrats convention say or do anything that won them votes?  I was not impressed, but then I am not a Democrat.