you'r correct just like all other leading fiat currencies don't have fixed total supply e.g dollar, euro, Yuan etc... they keep on producing more money under certain regulations and their values are still high. So to does etz no fix total supply, more coins mined under regulation of community.
you may ague that fiat currencies are losing their value but it has nothing to do with the fact the don't have a fixed supply.
If there is no fixed supply where does the number 20k etz for a node comes from, i mean why its a fixed number not a function from an epoch or smth? One could just gain 51% nodes, given the extreme disproportion of coins distribution. There are wallets with millions of etz. I mean this coin could probably work in real world but this totally doesnt add faith in it. And if it doesnt gain faith, people not gonna buy it.