Probably we will lose some hashrate but the difficulty will adjust as there's fewer miners and the fee become profitable enough for the remaining miners to keep on mining.
If it suddenly stops, it will be difficult to sustain mining on transaction fees alone. This would certainly put security at risk and the future of bitcoin would be uncertain. But only time will tell whether it can survive. I don't think that will happen at all. But if it does, the market would be completely destroyed.
Is it practically possible under any scenario ?
It's literally coded onto the blockchain so yeah it's impossible unless consensus agreed to change things around, just my understanding though, correct me if i'm wrong.