I ebike and the combination of an old rusty bike plus a large lock seems to stop thieves, even though I leave it on the street 247. I take the battery in though. And have a funky diy paint job. Also even if it was stolen it cost less than any of a years tax on the car, one service on the car, one replacement shock on the car etc.

My way of shopping with my bike is either taking my obviously pricey bike, which I can just walk into the supermarket without anyone thinking it could be left outside, or just take my old 25kg bike that's kind of not worth stealing and lock it somewhat close to the entrance just in case.