If there is no volatility then Bitcoins will only be a junk coin that is no different from stablecoins or Fiat, so what will be the advantage of bitcoin if there is no volatility and price fluctuations?
Sorry, but that's so very wrong in so many ways.
No volatility doesn't mean no volatility against a f**t poocoin. The f**t poocoin is volatile itself; namely its value is going to zero.
If Bitcoin had no volatility (in however reasonable way you define it), its USD price would still go to infinity, because the value of USD is going to zero.
Letting the central bankers and governments define a benchmark for value is like bending over and saying "Hey, screw me as much as you please."