Why are people buying ETH instead of L2s like Polygon?

I want to start off by saying I hold a bag of ETH and bought it a few years back before I knew what L2s were, and personally even though it’s not as decentralized as BTC, it has more uses cases and it has made me a believer in crypto as a whole. But what I can’t understand is, why are people just not buying L2s like Polygon, Arbitrum, etc. instead of ETH? I am not trying to bash on ETH I just genuinely would like to understand the reasoning behind this from people more knowledgeable in the space. Am I missing something? What benefit would I as a consumer and investor get out of buying eth over an L2 such as Polygon?

PS: I know some people will say Polygon is not an L2, but just like Arbitrum that’s its main use case and they are fully converting to an L2.