There’s a difference between the Ultimate BT (with hall effect joysticks and the paddles) vs the Ultimate 2.4g, which received BT support later on. They don’t use the same firmware.
The Bluetooth mode is made specifically for the Nintendo Switch on that model, on PC and Android you need X-Input mode, which is made available through 2.4GHz and USB-C.
I complained about that part too, and 8bitdo doesn’t seem receptive…
It doesn’t fit well into my life. With work, the kids and all the responsibilities that comes with it I can’t afford to sink a lot of time into it, so if I get a game I’ll focus on single-player games, or I’ll go with multiplayer games with a co-op to at least enjoy the game without it being a competition.