I'm sure if one day the price of ADA can reach $5, but for ADA to replace Ethereum, it will never happen, because there are already many blockchain projects that have very low gas fees than Ethereum, but until now the project still cannot replace Ethereum, therefore I believe that Ethereum will never be replaced and will remain in position 2 on coinmarketcap.
Aiming to replace ethereum is actually a very big challenge for any network out there.
Instead of targeting to replace it, better aim for more projects to be deployed under ADA.
Because the more projects that are successful, the better chance for this network to achieve $5.
Without continuous progress on the network, it would be hard for them to attract developers as well as users.
But if they see large number of projects that are successful using their network, good things will follow thru.