I have been away from the insurance sector for a couple years now, but before the electric car market was evaluated as its own class. This creates a huge problem because you can't distribute the claims optimally. If I simplify it you get (electric car insurance claims/electric cars that have insurance) + operation costs + profit %. Whereas in normal cars, your premium is decided based on the drivers age, previous accidents, car's age, car's color, the horse power, where the person lives, how much they drive etc. In the company I worked for we optimized the premium with over 200 data points.
You can't use the same optimization regarding electric cars because the market is so small and the data isn't there yet. Moreover insurers increase premiums to be on the safe side.
They continue to be just a brokerage in a handful of states so they don't even underwrite policies. If the margins were actually good they would have gone national and began underwriting policies themselves by now. Insurance is literally free money when you have a risk that competitors assess incorrectly.