I'm pretty sure altcoins will stay for a while. A lot of companies and corporations are trying to gain some market share from this and I don't think all of them are useless. You don't even need Bitcoin to crush those shitty altcoins since coins like Ethereum, Monero, etc are definitely going to outlive them. I expect there will be more cases like FTX, Celcius, etc in the future. The market will continue to filter shitty companies that promise 20% annual return as the only way to keep their business afloat. It's like what mk said, most of the altcoins are moving to their own category and do not compete directly with BTC.
What are your views on the future? I clearly know that the persistence of beliefs is often not so strong, and few people can hold Bitcoin for a long time.
We got a nice cycle if you take a look at the past. A bull market comes, lots of companies get mainstream, and shortly after that they go bust after the bear market starts, some revive with another name, etc. You will be surprised to see that a lot of users are holding BTC for years, and the number of 1 BTC holders is increasing every year. BTC will definitely stay, while scam/shit tokens will die sooner or later.