In Europe they are. All new chargers in Europe use the CCS2 standard, and teslas have a CCS2 socket. NACS is not suitable for Europe, because of three phase AC

In Europe they are. All new chargers in Europe use the CCS2 standard, and teslas have a CCS2 socket. NACS is not suitable for Europe, because of three phase AC charging (which makes home charging much easier/faster than in the US). I think all of the V3/V4 superchargers are open to all cars, otherwise Tesla wouldn't get government funding for expanding the charging network (at least in the EU, maybe UK changed that after brexit). Interestingly it's still mostly teslas charging there, although superchargers are one of the cheapest options to charge.