believe me garages would rather be changing at 50,000 they need the work !! but as i said 100,000 is becoming the norm also returning to chains on some vehicles. Sparkplugs can be 80,000 + instead of the old 20,000.
Before any one says it , no, a cambelt self destructing at 9+ years 90,000 wouldnt bring work in it would probably write the car off..
The only instance i would change earlier would be in a taxi or delivery type vehicle with a lot of stop start driving, where most of the stress on a belt occurs.