jireh the provider as far as I know there is no feature length documentary, although there are many individual interviews, both by the Pokemon company themselves and independent eSports journalism organizations.
One of those is actually how I found out about the site in the first place.
I think the problem is just that the VGC scene is just not as big as the competitive scenes of other eSports (especially when you consider VGC doesn't even include every competitive player). And while there are quite a few competitive Pokemon players,
professional Pokemon players (as in, players who can make a living off their earnings or sponsorships) are rare, if they even exist at all. Ray Rizzo, probably the most successful player, is attending college and looking for work. Compare this to the countless StarCraft 2 professionals who drop out of college or high school and live their entire lives off income from their team sponsorships. I just don't think there's any serious money in the Pokemon scene, at least just yet.
I'm not speaking from experience but I don't think it completely takes over your life like being a professional in another game. There are not nearly as many tournaments and there is plenty of free time, enough for the best players to be continuing their education/careers and having a life outside of the game while still competing at the highest level. I don't think we really need a documentary to show the crazy lives of competitive players at this point, because honestly I don't think it's that much different from normal just yet.
In short words, I think the competitive Pokemon scene just isn't big enough yet to attract a serious feature length documentary filmmaker, although I hope it will be soon. If you're really, really curious though, interviews and articles give a pretty good glimpse, and there are plenty of VGC players on this site and on Nugget Bridge that you can always ask to get some insight.