Is this not mainly down to the footballing pyramid being too big? They can no longer generate the money they need to survive, for the most part a one off game against a top team every 5-6 years isn't going to paper over the cracks.
With how entertainment is changing and viewed by the younger generation I can only see it getting worse for lower league clubs. It feels a bit similar to trying to keep high street shops alive.
If you believe some of the wage sites Wrexham's weekly bill isn't far off Granada, who play in La Liga. That's almost a similar amount to Tielemans weekly wage.