If all you do is surf social crap, watch videos, and email/chat you do not need a full PC. That is why PC sales are down. People who are not performing “real” work do not need PC’s. It is not that complicated.
Since I retired I rarely use my pc and use my ipad for almost everything. I have a wireless printer so can print anything I need off of it and there are a slew of apps for almost anything you want to do on it. Correct you are.
I still love my desktop PC, but the only tablet I have is a first generation iPad. I do not look at the iPad as a "real" computer; but rather as a portable substitute. Rather than go into the room where the PC is, I just use the iPad for checking emails, surfing the internet, etc. If I'm watching a TV show, I may look it up on IMDB to find out more info on it. I can sit out on the deck and smoke a cigar and use the iPad for internet, email, ordering something online, etc.
However, I would never use an iPad for serious work. I don't like typing on it, and it is small for looking at spreadsheets, etc. I carry it when I travel to keep up with email and stuff. I can listen to music on it as I would an iPod, and watch/stream programs on it. I usually watch a TV program or a Bible study lecture on it while I'm riding my recumbent bike. I would never consider it a real workstation type of computer, but I have no complaints for what it is. I happen to like having both a PC and a tablet.