Hybrids are very complicated mechanically, I'm not surprised hybrid conversions aren't a thing.

EV conversions do exist, it's just that they're too expensive to be worthwhile. You mostly only see classic cars converted.

You pay $20,000 for the hardware, another $15,000 for mechanics to spend a week or two gutting and rebuilding your car and wind up with a car with a worn interior, suspension, steering, etc, no modern features and a short range for more than the price of a brand new long range EV.

If you want an EV, you're much better off selling your car and buying a used EV.