Is PoS a “store of value”? Why would BTC maximalists say no?

I’ve heard the founder of Solana make reference in passing to an idea that PoW networks shouldn’t be considered a “store of value”. Can anyone shed light on what exactly he means by this?

I know that “store of value” is treated as a technical consideration for a material or asset, and that something like scarcity would contribute to that value (but scarcity alone of course doesn’t make for a store of value). What other technical factors are required?

I personally believe that PoW chains are too wasteful of power to rely on, but I’m curious about learning to other side of the argument. Why shouldn’t we consider ETH2.0 or other PoS chains a real store of value?