So, will mass adoption stabalize the prices of Bitcoin and altcoins?
Nothing will chance, crypto has been very volatile since its inception so I don't think that the price could be stable, perhaps it will be less volatile. Remember that the market is based on pure speculation so that eliminates stability to begin with.
If the mass adoption of a cryptocurrency increases its price, volatility will only increase, but not stabilize. There will always be bad news and rumors, and at high cryptocurrency prices, the amplitude of oscillations will become large. Therefore, the higher the price of cryptocurrency will rise, the greater will be its volatility.