Ah, you're talking about the fewest number of regular votes that would have to change so that the electoral college would flip. in that case I'd say 42k and 77k are essentially the same number, given the large number of voters we're talking about. But yes, Biden's victory was tighter than Trumps in that calculus.
Although, in the situation you propose, 2020 would actually be a 269-269 tie. Which means any unfaithful elector could refuse to vote for their candidate and throw it to the other party. And even if no one did, then Congress would break the tie in a pair votes that would presumably go for Trump and Pence if people voted on a party line.
Although, in the situation you propose, 2020 would actually be a 269-269 tie. Which means any unfaithful elector could refuse to vote for their candidate and throw it to the other party. And even if no one did, then Congress would break the tie in a pair votes that would presumably go for Trump and Pence if people voted on a party line.