Parts have a life mentioned in distance or time. Usually cars who have been standing for long have never got their parts changed because they have never worn out, but have expired. You see material degradation happens over time.
Had the car been running, the parts would most probably have worn out and replaced many many times.
If you buy a less run car, the first thing you'd see is leaking radiator pipes. Next would be the frayed fuel line which would leak petrol (which is expensive) and can also cause a fire. After that most probably the brakes would start jamming (means when you remove your foot off the pedal the brakes would only partially release). Then engine/gearbox/differential or other fluid retaining seals will fail. After that the mechanisms for operating windows etc. (whether powered or not) will fail. When a car which has usually been standing in shade will see a few days of intermittent sunlight and dark the door/window rubbers would crack.
Since the tyres would have also expired but have a lot of groove left, they are also dangerous.