In the last two elections, I was more concerned about (1) trying to stop the SNP from winning all 59 Scottish seats, and in a constituency where Labour were the best-placed to win, voting Labour seemed correct; and (2) doing essentially the same thing, while also wanting to avoid a Tory landslide. For both of these objectives, voting Labour was the only logical option -- not because I wanted to see a Labour government, particularly, but because they were best-placed to stop parties I wanted to win even less.
The same might be true in 2022, or even earlier if there's another snap election. Certainly one can't examine Labour in isolation, decide that they are not fit for government, and therefore vote Tory with no analysis of that party. In addition, there are local factors to consider, such as which MP I was voting for. If I were to find myself in Keir Starmer's seat I'd vote for him; if instead I were in Corbyn's seat I might vote Lib Dem or whatever just to spite the guy.
In practice I'll probably end up north of the border again, in which case I'll be heavily motivated by trying to keep the SNP out, as I would rather see us remain a United Kingdom, thanks very much. If that means voting Labour to achieve that end, so be it. But until such time as we have a voting system that makes it worth my while voting *for* a party rather than *against* one, then how good or bad Labour is as a party is fairly low on my list of priorities at the ballot box, to be honest.