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.