Ofcourse there is a warning message
Have you read it? What you did not understand?
I understand that it would be better to use more secure wallet...
MEW is extra secure, you have to be careful on how are you accessing your account
I use Ledger or by entering my private keys, always entering to the MEW site by my bookmarks, to avoid pishing sites or other scammy sites
if you do not trust MEW install on your phone Coinomi, Guarda or TrustWallet app