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.
Why would something that was made to be unstable, will still be expected to be stabilize through environmental or such different external factors? While the large adoption could stack up stone in the balance scale, and it could look like it can balance its price behavior into stable one, but shouldn't that be happening right now? While we still don't get the most of investors globally, price should be stabilizing right now through its lifespan throughout. I even think that Bitcoin will be even more unstable in mass adoption since there will be high demands of buys from investors for obvious reasons.