Difficult to do on a network which has too many services to actually function properly in some areas.
I bet you love people like me
Would shifting the schedule works ?
The Schedule might not be the issue, certainly in the UK, trains are scheduled in such a way that they should be able to work on paper - whether this works in practice is a different story. It could be your signallers are too slow clearing a train through, it could be that there is a temporary speed restriction somewhere, forcing the train to run at a speed slower that it's timetable, it could be the platform staff take too long the dispatch the train, or the crowds take too long to board the train. There are so many variables, especially with Passenger trains.
Likewise, cities like Tokyo would practically collapse if the trains weren't punctual - when you have stations running express trains every few minutes, you can't just have regular five minute delays. So they basically also have no other choice but the make sure everything runs smoothly.
The UKs system is very much in the same boat now though (at least in some areas). We are running express trains every few minutes, alongside Semi-Fast and stopping trains, and when the poop does hit the fan, these can all have a knock on effect on one another.
One of the main reasons we're proceeding with HS2 despite large opposition is because there just isn't the capacity for (many) more trains on the West Coast Mainline, and certainly not Express trains (Ameecher might know a bit more about this than myself). And unlike the rest of Europe, we can't run double deck trains either; We'd end up taking down bridges everywhere.