Is part of the problem also access? Its not improved much.
Money has been put into trail centres, but not linking up existing tracks/bridleways/working out linking sections, so people have relatively easy safe local loops which encourage families/kids to get into riding off road? Loads of these in France which are well used.
In Scotland there are sensible access laws, lots of adventure riding potential, but still rubbish in England and Wales. I know there were some moves from ST to try + make something happen. Local advocacy by the likes of Cotic has made a difference in their community, but what about the bigger bike industry? Putting something back, that will help their future sustainability?