Faults on the more modern signalling systems can affect larger areas than previously.
For example, if one relay fails in a Route Relay Interlocking the issue is limited to just what is controlled by that contact, or whole relay, and the amount of equipment that is controlled by one relay is generally fairly limited. In a Solid State Interlocking area though, there might be a couple of things controlled by one signal or point module.
The fact that the equipment is more spread out can cause problems with the speed of fault finding too, and issues are more likely to be reported publically where they cause significant delays. A track circuit is limited in length, so all the fault finding is generally limited to one small area. With an axle counter fault it's often a case of going one place to carry out a diagnostic download, and then back to the next town to investigate the equipment out on the ground, which obviously takes time.
Maybe I'm biassed slightly though. I'd much prefer to be working on old stuff any day, and it strikes me as more solid and resilient; hefty, reassuring lumps of metal, wood and bakelite. Now it's plastic and fiddly bits that wouldn't look too out of place in a toy box.