Don't think there is much that can stand up to a grinder. There are some new designs though that make it harder.
I replaced it with this:
https://www.amazon.com/Seatylock-Mason-Bike-Lock-Patented/dp/B08SMJD4K1
With a double lock and triangular bars once cut they would have to do some heavy prying as well to open it up. But none impenetrable. Keep it more in view now also.