> Any decent motor these days is a brushless DC motor
Most applications are perfectly fine with asynchronous motors which don't require extra power electronics. The increase in efficiency from IE3 asynchronouos to IE4 synchronous/SRM/hybrid is pretty small and costs a bunch.
Depends on what it is. Even the little fans in desktop computers now are BLDC now, with the controller fitting on a tiny PCB inside the hub of the fan. They're simpler versions, though, with hall-effect feedback rather than an encoder. The power electronics these days are dirt cheap.
> Even the little fans in desktop computers now are BLDC now
Those are at the lower end of the power spectrum of electric motors (which spans approximately 10 orders of magnitude from a few mW to hundreds of MW) and have been BLDCs for a very long time. To see something else in a PC you probably have to go all the way back to the IBM PCs.
> The power electronics these days are dirt cheap.
For a <1 W fan, yes, but when you want to run a 5.5 kW saw it still costs real money and the motor is more expensive.
Most applications are perfectly fine with asynchronous motors which don't require extra power electronics. The increase in efficiency from IE3 asynchronouos to IE4 synchronous/SRM/hybrid is pretty small and costs a bunch.