“any bluetooth mouse” needs to be paired with either a keyboard, or one of those split keyboards, or a gamepad in the other hand and none of those are very conducive to playing a game from the couch.
I’ll admit I haven’t tried the MouseMode at all, let alone on my lap or on the couch next to me but it sounds extremely novel and likely to catch on if it could work well.
Just adding here that when I first got into PC gaming, I was really into Battlefield 3 but hated the M+K controls for any of the vehicles so I would pick up my wired gamepad whenever I got into a vehicle.
If we had something that seamlessly mixed the strengths of both input methods, as it seems that the Switch 2 JoyCons do, that would solve so many of the problems I have with playing vehicle-heavy FPS games, or 3rd person action games that also include aiming a ranged weapon.