MS Office is notoriously resistant to running in Wine (haven't tried it myself) and, with all love to LubreOffuce, it's clearly the poor relation.

I've usually been able to get windows software running, but it's not always easy. I borrow my wife's laptop to reprogram my gaming mouse, for example. Couldn't be bothered any longer to dick about with wine.

But this is slightly beside the point: many have to use the allotted machines at work, which will tend to be windows (or maybe mac). That's the audience for WSL. It is an escape hatch for wage slaves.

The original WSL translated syscalls. It was a very tight integration. It was not perfect, and i should think it was a massive ongoing effort. I think it's an elegant approach bit i can see why wsl2 is essentially a vm. I never did any benchmarking, but i suspect that what wsl2 loses in disk performance, it gains in kernel performance. I never found either variant slow, and my corporate laptop was shit. My vagrant stack was diabolically slow, though.