There are many altcoins in the market, they are very good, though the owners of the big companies are very little trusting in Altcoin. However, there are many coins to invest instead of Bitcoin. If the market can be well monitored, it is possible to find many good coins.
I can't advise anybody to invest long-term in any altcoin. Time and again, I've been proven right in this. If anybody wants to take a risk in altcoins, it should be short-term nd take profit immediately they can.
If you look at the top 10 altcoins, if I'm not mistaken, only Solana has passed its previous ATH recently. People who bought Ethereum when it was $3500 are still waiting to get their capital at least back, not to mention making a profit, that's if they can wait that long. Most would have sold at a loss and cut their losses. People who took profit at $4500 are the winners in Ethereum.
There may be good altcoins out there, but I've not seen one that is as good as a long-term investment. Invest short term, if you know what you're doing, take profit and move.
If this happens and it's the last one - attention of the investors will turn to said alts.
If not - then, yeah, more time is needed for them to get to their new heights.
That's my opinion on it, of course.