Can you start your own product and compete against these ?
Also, technically, Twitter has 336 million active users per month [1], Snapchat has 200 million daily active users so we can easily double that amount for monthly usage [2], while LinkedIn claims 550 million users, but the monthly visits are about 100 millions [3]. Whereas Facebook is indeed 2.2 billion monthly active users [4].
All of these three huge players combined still only add up to less than a billion, notwithstanding people who are counted thrice by using each platform. I'm surprised how huge the gap remains.