Currently on Coinmarketcap there are 11,065 coins/token, this is indeed a large number. And it keeps growing. Altcoins exist 2 sides good and bad.
There have been many great Altcoins and overcome many disadvantages of BTC such as: ETH, Dot, Solana, Polygon,... We have also attracted a lot of non-crypto to the crypto market.
Besides, there are many altcoins that are scams, they take advantage of investors' trust and deceive them.
It's all up to you, Be smart in a market full of scammers