That's clearly false.
Trump still speaks perfectly clearly for hours at a time, despite his long work schedule.
Compare that to Biden, who rarely spoke in public, and when he did, he usually only took pre-scripted softball questions in ice cream parlours while surrounded by paid actors.
In the brief moments that he was on camera, ad-libbing, he pumped out gaffes faster than Kamala gives squeezers.
Just remember that Biden passed up on 90 seconds of free airtime during the Superbowl in an election year. That 90 seconds was worth over $25M. And the only reason he didn't do it is because if it turned into a gaffe-fest, CNN et al wouldn't be able to keep a lid on it, because it would instantly become a defining moment for all Americans.
What "swamp tasks" is he performing? I don't see him going off-script, based on his campaign promises.