End of the day, locking your bike outside is a losing battle. Whether it matches up to an angle grinder or not is not really the point, it just prevents opportunist theft.

The goal of locking your bike is to ensure bits don't go missing. However, what you're really trying to do is protect your investment. Locks stop bits going missing, but they don't protect the investment. My bicycle was locked overnight at Bristol Temple Meads train station (which I wrongly assumed was a secure-ish location). The thieves didn't manage to break the lock, so instead they just vandalized the bike so that I couldn't use it either. I sort of wish the lock had just given way, at least that way the bike might have provided some value to someone, somewhere.