Lololol
How the fuck can Phil have back issues?! Unless god is a detractor and saw it fit for his purpose to fuck with Phil’s back.
He gets zero exercise yes, but he has also done zero back breaking work of any kind.
And if Phil had some sort of degenerative back disease or anything of the kind, I’m pretty sure he would bring it up on a regular basis. Like the back issue the miraculous Seattle wind cured him of.
The story of Phil's back issues is a complicated one, only because Phil has made it that way. From the way he hobbles around, has to have extra support for his back and the constant rocking back and forth that actually is something people with back issues can do to alleviate pain, he does have a back issue. However, Phil has exaggerated the severity of it and has given many different stories as to how it happened.
When Phil first talked about his back, he said that he didn't know how it happened, something in his back just slipped out of place, nothing he could do. The next time he talked about the origin of his back pain, it was from a flag football game he played at a family get-together. Then he tried to tie his car accident to his back issues, further complicating the story of the car accident where in previous versions he didn't talk about back pain being a result from it. So really who the fuck knows what the actual story is, but in all honesty the most likely is the first version of the story, where it just sort of happened without any real explanation, because that does happen quite often. In Phil's fucked up brain, he had to make it a more "exciting" story to tell and couldn't decide on one thing.
As for the severity, Phil claims that the back issue prevents him from lifting heavy boxes, running and even driving on the highway. Phil admitted that during his early years on YouTube when he pointed a camera at the TV, he would play games while laying down on his couch because of his back. For years, Phil talked about getting surgery to fix it because it was such a burden, but it was a risk because the surgery could also make his back worse. This is pretty plausible, a botched/failed surgery is almost always worse than the original problem. What complicates this is that over the years we've seen Phil do physical activities that someone with such extreme back pain wouldn't be able to do, most notably dancing. And when Phil moved to Washington, he unironically claimed that the "clean Seattle air" made his back feel better, but apparently not enough to where he has to use a wagon to take groceries from the car to the kitchen.
At this point, Phil's back pain is just an excuse for laziness.