I dont know that you could port Bitcoin onto Grin. So it is a threat.
But their monetary policy is fuxxed. Big mistake having an endless emissions. Same trap Monero fell into.
So that significantly reduces the threat.
No that is untrue, an emission is a necessity for a currency that's goal is use and low volatility for a plethora of reasons while a cap is good for a SOV which Btc is.
Endless emission means no value, this is, literally, economics 101. No value means that it is useless. Those guys might be good coders but they know absolutely nothing about economics.
But don't take my word for it, just wait until their wishes meets reality.