The user-friendliness that i meant has nothing to do with the design and user interface of the wallet, but with its possible correlation with other altcoins in a simplified ecosystem for any user, what I mean is that it is as simple as you make a transaction to x person in any cyptocurrency having only ''a one wallet address or their email, user etc...''.
This is called a centralized exchange. I doubt it goes better than that. If person A wants to send money to person B, but A has bitcoin and B wants monero, then you need an exchange to do the conversion. Theoretically, it can work decentralized, but it's a lot more expensive due to the on-chain transactions needed to make use of the scripting language of each crypto.
So, in summary. It's not a UI problem. It's an economic problem.