I think there are a few issues at play here.
First, almost all digital cameras perform to at least an acceptable standard for 95% of users. An accomplished amateur or pro can pick up a £70 camera from a shop window and get decent photos with it. This wasn't the case with digital cameras even 10 years ago. Longevity of digital cameras in recent years has been much better than it was prior to 2005 or so. Put simply, people are generally satisfied with their cameras and don't buy new ones often.
Second, for a whole bunch of people their phone is now their camera. They're not buying cameras, prints or accessories.
Third, digital cameras are no longer something new and exciting, nor are they especially cool or hip.
So necessarily, money spent on digital photography is slowing. Heck, I use my DSLR and a compact digital and indeed my phone a lot...but the last time I actually bought any digital photo products was probably an SD card in 2014, and some printing paper in 2015.
Whereas there is a measurable upswing in the analogue photography market...sales of film are up....ditto chemicals, prices of used gear are increasing....which all means people are becoming interested again. Sure, it will never be as big as it was when your choice was 110, 135 or 120 (rather than film or digital)
Note also the significant niche that Fuji have nurtured with Instax.
I'm thinking that before 2019, somebody will bite the bullet and produce a mid spec film camera at an affordable price....comparable with a low-mid range DLSR or top end compact.