Sometimes I think..
If now we have a fast network with ecology as prosperous as ETH and low tax
Why we need L2 network and ETH..It seems like a deficient network repairing itself constantly.
And POS is without justice that the strong will always be stronger.Blockchain need justice and every one is equal.
I want to see you mates' opinion.And if possibile,please recommend me the best cryptocurrency undervalued now thx.

It's the believed of Vitalik that Ethereum will be more secure if they go POS. That was his statement 4 years ago, before this whole mess with the exorbitant gas fees. But looking back right now, it just make Ethereum worst and more centralized, so there is a trade off the Vitalik is referring to, security vs centralization.
So you will be the judge whether he achieved something or not.
As for the undervalued crypto, it's a guessing game right now. We could recommend something but it might not be big in the future.
The best approach is to really do your own research.