ANSWER:

How can one be close friends in any age with one who backbites, slanders and lies!?

No one is perfect and one has to look for friends that have shortcomings that are not toxic or sinful.

Friendship in this age: As there is a say that: “your network is your net worth”. Nowadays, its evident that those who have waastas/links are worldly successful. But as you & other scholars point out that avoid friendship with those who backbite, toxic towards you & your religion. But at the same time you say no one is perfect.