I absolutely have no problems using my PC while lying on couch. As Zero said do not try to WORK on PC while lying, especially when you need to type a lot or modelling something precisely etc. I organized my living room so that now I can play and browse internet browsers lying with ease.

1. I can conveniently browse Internet using wireless mouse, read news, articles, forums etc.

2. I can instantly watch video files, any av coding, any container.

3. I can easily listening to music from any service, from preferable audio player any playlists, quickly making queues etc.

4. I can play turn-based games with wireless mouse very conveniently.

5. I can play any other game with Xbox/Steam/(or even DS4) controller in Big Picture mode.

---All of that while LYING on my couch.

It depends of the situation and organization.

So I picked a coffee table with specific height so the arm while using mouse was situated parallel to the floor and checked that the table isnt blocking the part of screen while lying and watching. I have wireless mouse. System DPI setting is 125%. Chrome is set to 150% page zoom.

6. I can type while sitting.

7. I still can play with k&m while sitting.

8. I still have a PCs in other room with kvm switch, monitor and chair. And as Zero said you can easily use Steam Link for your TV if needed (if you can't handle two pcs or dont want to).

Yikes! I definitely couldn't do that setup in my living room. The keyboard and mouse would be thrown down the hall in less than hour.