If someone wants to talk to me I get a popup on my Messenger app on my phone, and if I get an event invite it shows up there too.
Good for them, but they seem to mistake it as some sort of universal lifehack.
Does it have to be universal to be useful? Helping 0.01% of the US Facebook userbase save 1 hour every week is still huge...
So, that's one downside, I think.