I don't watch basketball, so I am speculating, but isn't this a case where defence hasn't yet adapted to the new attacking strategies? Wouldn't you expect that in a few years teams will be better at defending against 3s, reducing their expected value and therefore swinging the pendulum back towards more 2s?
The Nash equilibrium should be that the expected values of 2s and 3s are equal. If you're off, you would expect a trend toward that equilibrium, possibly with some overcorrection.
Ironically Steve Nash didn't shoot enough 3s, so his Nash equilibrium was pretty off.
In all seriousness, yes, there's a lot more to modern basketball than just "take more 3s". It's more like "try to get dunks and layups, but if that doesn't work get 3s, but also mid range is still valuable if it softens up defense". And defenses have learned to scramble and switch to cover a lot of 3 pointers, but that can still be exploited with cross court passing and switch hunting. Check out some cool plays here: https://www.youtube.com/watch?v=qo-V_ujmMFo
The Nash equilibrium should be that the expected values of 2s and 3s are equal. If you're off, you would expect a trend toward that equilibrium, possibly with some overcorrection.