There's no doubt Griffiths was a top class striker.
I'd be amazed, however, if he ever performs at that level again as he just isn't managing what appears to be mental health issues. Sadly, I've seen nothing in the past few years that suggests he's likely to fare any better with any other team.
On one hand, playing football probably gives him a level of comfort and stability he needs. On the other hand, walking away from football for a year or two to focus entirely on his health might be exactly what he needs.