There's "slow learning PPLs" and then there's 200 hours, that's absolutely insane.
Sure we all learn at different paces, when I started off as a young instructor I believed that everyone could get the hang of it with enough practice, but after a few years' instructing and some of the things I saw, I changed my opinion. There have been several cases of people that I just know will NEVER make it no matter how much time and money they throw at it, they just haven't got the spare mental capacity / attention span / spacial orientation skills. Slightly un-pc to say so but it's true. I have given one poor student my honest advice to give up the dream before, it wasn't an easy thing to do but this individual was about to remortgage everything they owned and put the kids' education fund on the line to follow their dream they didn't basically have a hope in hell of achieving - and that was long before 200 hours had been logged (although it was somewhere after the 48 to first solo).
If your mate has received good instruction and hasn't got the hang of it by even half that amount of time, then someone should have given him a very serious talking to about where he's going with his career.
The PPL is the first small easy step on a very very long and difficult road and it gets a lot steeper and a lot harder from there on in.