The only way to get people to stop worrying and shying away from Bitcoin, is to banish the volatility aspet of it, naturally.
I put emphasis on the word "naturally" because you cannot force a monetary process to establish itself in a few short years. The price and users must gradually reach an inflection point on their own.
It is similar to implementing the Euro as the official European currency. By no means were the governments rushed to scrap their central bank currencies, they were give ample time (about a decade or two IIRC) to phase it in, in stages.
So Bitcoin, and anything that wants to follow it in market capitalization, must be introduced to the public in phases, which could take a very long time.
The rest of the altcoins that do not stabilize can disappear (e.g. Solana), I have no pity for them as they only serve to give larger cryptocurrencies (and crypto in general) a bad name in the news.
If Bitcoin is going to be a solid and reliable currency that is used for into the future it needs to act like the biggest existing currencies which have reasonably low volatility like you say. Speculators are bad for the future of Bitcoin, because they are people who have the most fear and are the most erratic in their dealings with the currency. Volatility can also breed a lot of misunderstandings, put off newcomers who might only have sparse knowledge of how it works and create warning bells for politicians who will be more inclined to regulate against them. Stability will breed confidence and it'll actually be good once all the possible Bitcoin are mined, even though the newly minted stuff is in much lower supply than it used to be.