I'm considering getting a powerful ebike...
I'm mostly concerned with a glitch/failure that could prompt the e-bike to take off on its own...
I figured with all the strict federal laws, checks, and safety measures, my car is a much safer vehicle than an e-bike off AliExpress
Seems simple enough. Don't get such a powerful ebike, put the money towards major brand quality rather than more performance (and probably shorter lifespan) with some Chinese seller on Aliexpress who has no accountability.
I'd be far less worried about it taking off on its own and instead, some mechanical failure that puts you on an unintended course into traffic.
In some ways motorcycles are safer. The quality control has to be higher to be on public roads. The noise of a combustion engine helps fellow motorists notice you. The far sturdier build allows more recovery from potholes and other road debris. The greater potential speed allows you to travel at same rate as other traffic so they're not tailgating or passing you too close, or to get away from problematic motorists.
As far as glitches go, inspect and maintain the vehicle on a regular basis... like your life depended on it.