People have taken apart the Tesla Model 3 inverter and we know what they've found. Here's a hint: it's not a stack of 100V MOSFETs in series.

Depending on the model (SR+, Performance, etc), it's either SiC MOSFETs or IGBTs. And there's only one in series, not 10 or 100.

Also, please do me a favor and never design power electronics ever...