The problem is, there are many scam new projects created in crypto everyday.
Unless we have time to do some researches, we would never know whether it is a real project or not.
Polygon or Avalanche were new project back then, but some investors who has done their due diligence invested on them and got their profit.
Even if you make your own investigation about a project in which you are interested that doe not mean that you will find anything wrong with it, and what better example than what happened with luna? The coin reached the highest levels that an altcoin can reach and yet it collapsed because at its heart it was a shitcoin.
And unfortunately this is not the first example of something like this happening and it is only the most recent one, so with this in mind it is better to avoid altcoins as much as possible right now as the possibility that a project can overcome the adverse market conditions are low.