Reality is that if a bike thief really wants your bike, there is nothing you can do to stop them, aside from being right there and physically stopping them. You need to just make your bike more inconvenient for them to steal. Locks are good, locking it too something is even better. I once had 2 disk locks on my bike and an alarm, they picked it up and threw it in the back of a truck and drove off with it while cutting the alarm wires at 3pm in a busy shopping center parking lot. Luckily most bike thieves know nothing of electric bikes and the black market for electric parts is very small right now, so they have less incentives to steal an electric bike compared to a gas bike.