IMO a large part of the issue, and why this is remaining a story, is the response when Cummings was found out. Rather than just admit he was wrong and apologise the entire Conservative party has doubled down to try and cover for him.
We've had the likes of Shapps and Gove sent out to cover for him and a constantly changing story riddled with inconsistencies. And thats before you consider how it stacks up against the account Wakefield has given multiple times.
Not to mention in trying to defend himself he's said he's gone back into work when he should have been self isolating, carried out unnecessary travel to Chequers and the laughable testing his eyes excuse for going to a local beauty spot with his wife and kids on his wife's birthday.
He did something wrong and got caught. Own up and apologise. Obviously the problem now they're so far into a web of lies and misdirection he would have no choice other than resign, or be sacked, if he does finally own up.