Like opensea? While it is a marketplace for NFTs, the fee is certainly a big concern but it seems that most of the networks for altcoins aren't that expensive at all. But a time when the demand gets higher especially in the ERC20, the fees are also going to increase together with the demand.
Whilst there are other networks that are being supported for each coin, you can consider that as well that your marketplace is open for different networks and wherever is the customer is confident without having interruption and problems with the fees.
Opensea is one among many marketplace for NFTs. I'm thinking a real marketplace where people meet to exchange good and services against cryptocurrency. Indeed fees would increase when demand increases.
But on low-fees blockchains, publishing a product would cost less than a dollar.
Furthermore, i think fees could actually be leveraged to protect the market against spamming and scams.
IMHO, ETH was once a low fee transfer for most of its tokens before known as ERC20 tokens. But once the demand has increased, aside from its growth, the spams and scams will be part of it. Wherever the people are, there goes the scammers that will try to fish(phish) a lot of those people that are using that blockchain. That's why, there's actually no solution for that and those boasting their TPS are because they're not yet crowded but soon, we'd see how they're going to respond on the demand that their network is having.