I'm still very confused about Bitcoin. Now, I opened a wallet from blockchain, ok? And you know, I have the identifier, pass, mnemonic info and etc...
Do I need to something extra? I mean, isn't this enough? Why people are using other wallets?
you need to keep your Identifier, and recover phrase somewhere safe. preferably written on a paper.
also use a strong password and make sure to enable two factor authentication for extra security.
now you only need to give others your bitcoin address in order to be able to receive bitcoins.
people use other wallets because they are more reliable and safer.
if you have significant amount i suggest you to look into other wallets specially try to use a cold storage for big amounts.