The way DNS works in i2p makes it unreliable and vulnerable to attacks. It wouldn’t be to hard for an adversary to do a man in the middle or even do a fake version of a site. Also resolving DNS names is hard and takes a lot of effort.
Honestly the entire system needs to be rethought.
It would need to have some sort of overhead cost to make attacks unfeasible. By adding that you would then be slowing everything down and creating a new source of problems.
It isn’t a winning battle I guess.