With clock face scheduling (like in CH and planned for Germany) they very much do since schedules are optimized to align with periodicity.

On some Swiss lines it's fairly common to have trains recover their delay at departure (which also avoids cascading impact).

https://en.wikipedia.org/wiki/Clock-face_scheduling

Everything always runs at 80% down to even 50% for normal 99% of the time operation. Not just trains, everything.

What was the old chestnut? A traffic jam is a highway at 100% capacity? Something like that, can't remember who said it. Niels Pfläging perhaps?

i don't know where i implied that but it is well known that this is the case in order to give buffer time.