How can we be sure ETH prices won't collapse once gas fees go down?

Right now you need a fairly significant amount of Ethereum in order to transact on the network. If we imagine a world where sharding and layer 2 solutions have driven down gas fees to almost nothing, why wouldn't the price collapse? Hypothetically, I could do all of my business on Polygon or the Visa Crypto Network (or any other hypothetical centralized sidechain validated on Ethereum). There would be no reason for me (the average person) to transfer my assets to ETH unless it was the only bridge to transfer my assets from one chain to another.

Sure I could stake my ETH but there are plenty of other assets I could also stake, which more than likely have a higher yield.

Just something I've been thinking about lately, thanks!