No. No one needs linear gate drivers (for better or worse).
If you want to make a MOSFET amplifier, you probably need more than just an analog isolator, rather a high side current control.
Hmm, I drew up an amp along such lines years ago, don't know if I have it handy...guess I'll have to print off a copy, here:
https://www.seventransistorlabs.com/Images/Power_OTA2_Sch.pdfIt's a diffamp, level shifter (constant currents), local diffamps (sets current through respective transistor), output. Common mode current sets quiescent bias, differential input voltage sets output current sets output voltage. So it's a transconductance amplifier first and foremost hence the name, with voltage feedback to give a fairly ordinary voltage gain response.
The simulated bandwidth is quite good, something like 10MHz, but the phase shift is quite large at cutoff (>180°?) so can't run in a voltage feedback loop nearly so quickly. It's not clear if a real version would actually achieve that much bandwidth, but 100s of kHz seems likely.
Note the 6V "batteries"; I was going to use a pair of DC-DC modules for that.
Never did build it, but made most of a PCB, IIRC.
For higher voltages, the high side level shift will be that much more sensitive to voltage swing; a differential stage should be used. A contemporary digital example is here:
https://www.seventransistorlabs.com/Images/CMBuck_Output.pngBut anyway, the point is, by putting some control circuitry at the transistor, you can solve one of the harder problems otherwise, which is setting current in a reasonable way. A traditional audio amp structure (diffamp, gain stage, follower) assumes the output follows the gain stage voltage, which is necessarily the case for BJTs, but not with MOSFETs, and isn't easy to adapt for N-channel types (P-channel types aren't available in high voltages, or high speeds now that SiC MOS is an option too). This control can be integrated as part of the level shifting so you dilute the impact of not having an explicit isolator, or don't much care in the first place.
Tim