No definitely most of these coins are not needed. One could argue only a handful are actually needed. I mean for 99.9% of them they are just clone coins that are all marketing and no substance.
If you think clone coins or similar coins are not needed, then only Bitcoin can be accepted. You should understand the name first, altcoins = alternative coins, what does it mean? Those are alternative options besides Bitcoin. But although they are alternative coins, they should have a role, have a purpose, and have functions.