3. The media and national coverage
All NFL awards are awards voted on by the media. But comeback player of the year factors personal bias and emotions into the equation moreso than say MVP or rookie of the year. The media would have to get behind James' story in addition to him having a good, healthy season.
In terms of narrative, James' story doesn't really stand out significantly from the pack. He dealt with the same kind of unfortunate season-ending injury that a few other candidates went through. Odell Beckham Jr., Bosa, Barkley, and Burrow, are all coming back from knee injuries that are about as bad.
The case I would make is that it's been pretty much two seasons of significant injuries in a row, but again, James isn't the only player that can make that case. Barkley falls pretty firmly into that category after a high ankle sprain cost him to miss about half of the 2019 season.
The good thing for James is that the Chargers will have more primetime games with some fans in the stands at SoFi (hopefully, barring pandemic restrictions). But like I mentioned earlier with Prescott, at least a handful of other teams/candidates will be driving more headlines and attention should they stay healthy.