By next year we shall see the result of the Libra development and if its going to be a successful launch, do you think one day we shall see a facebook login button on exchanges like binance? Would you login to it?

I have seen this on websites like medium.com. Worse is taht not only binance but also kraken and bittrex

More hassle than you think. If your exchange account tie to Facebook then it open more trouble because now, you have to keep your Facebook safe from fishing, hacking,... and a lot of other stuff.