Yeah, that's a real problem. For practical urban riding, I use a beater fixie that I can replace for less than a car payment. I've had a few stolen, but that's across decades. This is probably highly dependent on your particular location. But I've also had cars broken in to.

Replacing the bike is actually a lot easier than getting the windows fixed IME.

Fwiw the only place I had a bike stolen was the secured underground garage in my apartment complex. Never had issues just parking it out front while running errands or other such stuff, or parking outside work during the day. I'd figure foot traffic would keep angle grinding down. I've personally not seen angle grinding done that brazenly before, seems liable overnight though where the thief has time to work and the assumption no one is awake to hear the grinder (such as what happened in the case of my apartment).

If I can't find a good spot to actually lock up the bike though I will just bring it in to wherever I'm going. Shops or restaurants don't seem to care if a bike is parked in the corner and you can thread your ulock through the wheels and make it useless to ride off with.