This is a very common fault, yes. Power supply issues in general. It is also not uncommon for people to replace e.g. Wifi routers because the wall warts fail.

It comes down to a few people don't knowing a lot about it - and I'm not blaming anyone for that, we all have our interests and most people have more than enough to do already to worry about what goes on inside their stuff.

Also, electronics are, to a lot of people in a lot of places, so cheap that they would rather just curse a little and buy a new thing, instead of bothering with taking the thing to a shop. And of course a few hours of skilled labour in a big city in the west might also be almost as expensive as making a whole new TV in a factory in Asia plus shipping, so it might not even make economic sense.