I'm still using MEW as I consider it one of the safest wallets out there. It's true some of its developers left to start mycrypto project. But that doesn't mean MEW is now an abandoned project. Just ensure you prioritize your safety by ensuring you don't enter your private keys on a phishing site.
Technically MEW is just an interface for creating your wallet, and I think you've misunderstood that MEW is the safest since it's very risky moreover if you access the wallet using your private key. The safest wallet is where you can access them without giving your private key or store them offline, the hardware wallet for example. MEW itself not recommend people to use private key as a method of login, since their site always got attacked yeah it's better safe than sorry, just a friendly advice.
Most of people thinks that MyEtherWallet is safe but its not. All online wallets are risky MEW for example as you copy and paste your private keys on the web, there are some people who made MyEtherWallet's copied website and many had turn their assets into ash because of that incident that is why there is warning on Myetherwallet's website.