Watching the Mahut/Herbert semi final match right now and there is barely anyone there watching. This is a semi final of a slam event! A sea of blue chairs... discuss.
Why would they, though? With how physical the game is nowadays, that would imperil their singles. And it's a low amount of money and prestige compared to singles.
I think the answer to the OP is yes, unfortunately. ATP made the wrong interventions when they tried to save it by shortening it; it instead reinforced the fact that doubles is second-class, and kept the death spiral going. (Death spiral: doubles is less prestigious, so top players play it less, so fans watch it less, so it becomes even less prestigious, and so on...)
It'll get worse until/unless the ITF and ATP actually try to save it, and if they do it will be a massive undertaking.
It was alive during McEnroe's era when he was simultaneously #1 in both doubles and singles. I don't think they had so many mandatory tournaments, if at all, in those days so the calendar wasn't so busy. If the top players played doubles as well it would get more attention but they have enough on their plate already so doubles, I have to agree with Dan Evans here, is left to players who are not good enough to make it in singles and TV won't give them the slots.