I recently discovered the Bias Resistor Transistors (BRT) / Digital Transistors as commercial solution for low power, cheap solid state switches.
This IC is offered by multiple suppliers (Rohm, NXP, Infineon, Onsemi...) and all of them use transistors of BJT type.
Why there's not a mosfet integrated solution for BRTs?
My first guess would be that since BJTs have higher transconductance, can deliver current faster and have lower capacitance, so they might be more useful to be used as simple gate drivers for higher power transistors.
However, I have found circuits where a low side digital transistor is used to drive a high side, low power PMOS transistor. Is that only for redundancy purposes? Just 'cause BRTs are very cheap? Wouldn't just adding a series resistor to the mosfet's gate a cheaper solution?