The problem with not learning languages is that it restricts you to computer-mediated communication. If you learn other languages than your own, even at a fairly basic level, there is a whole world of social interaction and culture out there that just can't be accessed with a machine in the way.
This isn't to say that automated translation is bad, I use it extensively, but not all interaction worth having is online.
The expectation is that AI translation will also become quasi-realtime, so for in-person interactions, too.
Many cultures will probably much rather interact with a foreigner speaking proficient AI translation, than a language-learner speaking with a poor accent and constant grammatical imperfections. Go to the Netherlands now as a Dutch learner who hasn't reached B2 level, for example, and people won't like it, it just wastes their time compared to using English.
This isn't to say that automated translation is bad, I use it extensively, but not all interaction worth having is online.