Replace "need" with "desire" and suddenly it makes sense.
People have a desire to socialize (facebook), people have a desire to be heard (twitter), people have a desire to communicate (messenger apps, phones), people have a desire to travel (automotive, travel), people have a desire to be entertained (netflix et al). Etc. Etc.
You don't really 'need' any of it, but there is a very high demand, and thus a big market.