I use different wallets for different purposes. I don't like multi-currency wallets because I don't like to keep all my eggs in one basket. I use Electrum for bitcoin and MetaMask for Ethereum and its tokens. I also sometimes use MEW. First of all, ease of use and security are important to me.
If you are talking about Myetherwallet app then I can't support you. I tried to move from the MEW website to apps but for that it was a very bad experience. I use Coinbase for BTC holding and Ethereum websites. New currency is involved in the cryptocurrency everyday, how many wallet will you use? One day you will lose your wallet or forget the password.
I use the web app of the MEW. I don't need to install the program on my phone or computer. You say that I can forget the password from my wallets, but this can't happen, because I write all my passwords in several places. But if hackers break into my one wallet, they won't steal all the coins I have.