Depends on the country. In some places they actually fail you if your car is dangerous

Roughly 50% of the NCT tests in Ireland fail.

Common issues are bulbs, tire inflation, tire wear, shock performance, and alignment.

Personally, with an old (2006, 200-300K km) car that we had to NCT every year, we would pass about half the time on the first time, and half of the failures were for BS reasons (e.g., one of the removable seats wasn't installed, it was in storage, or a tent peg dropped into one of the 3rd row seats when they opened it, and couldn't close it again).

Even with that NCT, when winter rolls around, 5-10% of cars have obviously broken headlights on any given dog walk.

Depends where you live, in most of the US yes, try that in Germany or France though

Where I am in Europe they will test and adjust them for you. My headlights can only be adjusted from behind, and I thought there was no way to do it without removing them. The inspector knew of a plastic gromit in the rain tray above the hood that can be removed to access the adjustment point.