I see many people saying they no longer want to buy any altcoins and are only focusing on Bitcoin

In my opinion, this is a huge, huge mistake. What should be done instead is to change the way you treat altcoins.
That is, not to buy them for the long term, because many of them disappear in the long run, but to buy them, ride them, and sell them.
Unfortunately, the era of buying something, doing it in vain, and then the next cycle recovering is gone.