Ada price and network fee

Can someone explain me the logic behind the network fee rates.
I understand and love the structure with a base cost and a variant cost depending on size.
But ADA network have goal of low fee/transaction , wich should be compared to what we have today a transaction fee of 0.05 usd 0.3 max…
With a network fee of 0.16 ada this would mean that to be relevant ada should be priced at max 1.87 usd.