Absolutely. Ridiculously underpowered bikes have always been an interest of mine, especially cyclemotors, i e. engine attachments for push bikes aka clip-ons. These were particularly popular in France where they were treated exactly the same as bicycles. I'm not sure what the current French legislation is regarding these vehicles. Here, we had (and still have) to have them registered as motor vehicles with number plates, insurance and (now) wear proper motorcycle helmets which seems ridiculous. However, In retrospect, it's not such a bad thing really with wayward cyclists ignoring the rules and the pressure to register bicycles and the complex rules on ebikes etc.
By coincidence, I am seriously considering purchasing an electric bike attachment kit for my push bike. I still ride it occasionally but at 82 I need a bit of assistance up hills and don't have the stamina I had when I was 20 when I would easily cycle 100 miles.
Fortunately for me, such kits (at the moment) are treated as bicycles if the motor is under 250 watts and limited to 15.5mph.