The less complex your train network, the easier it is to ensure trains are on time. France, Italy and Germany possibly have larger networks than Switzerland.

Then split your network into segments you can handle. Switzerland receives lots of international trains. Not only that; it has a lot of rail companies, serves even tiny villages, and has the highest use per capita in Europe. Size of the network is a lame excuse. German trains used to be fine. Now they're a disaster.

Switzerland has all public transport synchronized across the country. In any of the countries you mentioned they don’t even gave synchronized public transport at city level.

No, Swiss SBB is just generally very competent and has insane amount of traffic in comparison to any European rail.

The swiss have a more challenging geography and weather than Germany.

They also spend far more per capita on their train system.

All that and afaik they still manage to connect all important places.

Except that The Netherlands has the busiest rail network in Europe [1] and still manages to be second in that list.

[1] https://www.acm.nl/en/publications/acm-rail-monitor-netherla...