How does the system work with so many coins long term? If we start using multiple coins to buy things in our daily life, if we accept multiple coins as forms of payment doesn’t that feel unsustainable?

I’ve been thinking about this a bit. I’m sure it’s my brain being accustomed to USD but it seems weird to envision a world with potentially unlimited “currencies” to buy goods.

1) right now though I hold multiple crypto I don’t hold tangible currency other than USD. It would feel odd to carry pesos, and yen, and rubles, etc. I say odd only because it would feel overwhelming walking into a store and either seeing a) items prices listed in different currencies where my brain would struggle to compare which prices are best or b) every price is listed for every item and you get to pick which also feels overwhelming.

2) so then the logical next thought is to use an interface crypto to convert coins from what you have to what you need. Which makes sense but at the ground level if I want to buy a pack of gum why do I want to pay a fee (as minimal as it is) to turn my Alpha coin into Omega coin which is the only coin the store takes?

This is all just thinking out loud , the world could unfold very differently. But I just have a hard time believing retail stores will adopt infinite coins for tender. So what roles do the coins serve that don’t get adopted?