They don’t have spatial tracking so it wouldn’t

No... It really wouldn't, at least not without some extra infrared equipment (and a lof of it) joy cons only have enough sensors to do 3dof, and you really need 6dof for something like beat saber.

I actually very, very much doubt that 😅 I play it quite a bit and incredible precision is required, something the Joy-Cons do not have.

I don't think the gyroscopes in the Joycons are good enough for beat saber, but I'm not 100% sure