Since the launch of Bitcoin and Ethereum, What gap is responsible for the rise of other chain networks?

So I'm trying to understand the rationale behind the launch of most blockchain networks right after Ethereum came into effect.

I get that Satoshi started Bitcoin because he wanted an alternative currency to fiat which would not be under the control of the government. Then if I'm correct, Ethereum advanced what Bitcoin started by going the way of Smart contracts.

I really don't know which network popped up next, but I guess that the consensus model used in Bitcoin and Ethereum needed some rework, and that brought about the first PoS network. But since the very first PoS chain launched, there has been a crazy growth from Avalanche down right to BNBchain, Solana, Zetrix, Cardano, Proton chain etc.

Guess my very question is what difference exist between all of these unique networks… like are they are advancement of the other in some way?