U6 final fight in the manga was quite lacking though. Hit was more a joke than a final villain/antagonist.
I'll actually agree that the battle was lacking especially when compared to the Tenkaichi Budokai battles only because the climax was lacking. The entire battle up until that point was brilliantly executed. Goku makes it a clear point that he's merely gauging Hit's abilities and Hit responds by saying that Goku is naive and foolish for doing so. Hit initially has the advantage but Goku's brilliance is at play by responding to Hit's challenge by countering his Time Skip. Hit eventually acknowledges Goku as a fighter and responds to Goku's challenge by revealing his hands which therefore, reveals his own strategies.
Hit had been cautious up until this point but Goku's charisma and spirit for battling causes Hit to respect Goku and battle him directly instead of covertly. Goku ramps things up as a Super Saiyan and Hit responds to Goku's challenge by battling him directly. At this point, the battle develops into a tactical bout of who outpredicts who. The battle builds up tension for Goku as Toyotaro clearly illustrates both fighters' reactions during their entire skirmish. Goku is evidently straining himself whereas Hit is calm and reserved. This eventually reaches the climax of the battle.
Goku realizes he can no longer hold back and opts for Super Saiyan God. Because Goku's strategy had failed and Goku could not outpredict Hit's own predictions, Hit becomes overconfident, careless, and sloppy in his approach causing him to be significantly overpowered by God Goku. At this point, Goku is aware of the weakness behind Hit's TimeSkip whereas Hit is finally coming to realize that his technique actually has a blindspot. This brilliantly leads to the climax of the battle where Goku bets everything he has into this one attack i.e Blue. Same goes for Hit except this time, he conceals his hands, making it clear to the reader that Hit is danger?
What's the problem? The climax is rushed and there's no tension because Goku never seems to be in immediate danger. On top of that, both aren't gradually wearing each other down, trading hits, constantly catching eachother by surprise, employing new strategies, pushing eachother to their limits, etc. It just boils down to Hit being overpowered, then Hit powers up, gets overpowered again, and then we are led to believe that Hit is the victor of the match. There's no struggle in countering Hit's Time Skip because we are told Goku was aware that he had the power to counter it regardless. This is something the anime did very well.
Hit's Time Skip evolved to the point where Goku could no longer counter it. Goku is brought down to his knees and we are left to question how he counters it. And when he does counter it, both fighters push themselves beyond their limits to outdo eachother. This is something missing from the manga which removes us from the urgency of the fight. The climax and resolution of the fight is inherently flawed. But, the narrative behind it and the progression up until this point is pretty spectacular. Definitely wouldn't put Universe 6 as one of the worst. It's one of the better battles in the manga that doesn't drag on more than it should. Unlike the Goku Black saga and the current arc....