Why is train data shared with the Belgian gov?

(cross-posted from !opendata)

In Belgium, the national train service runs a protectionist bot-hostile tor-hostile website that chains users to an enshitified js-plagued GUI webapp. You can only query one day and one destination at a time. It’s the typical shit-show that consumers give in to for this kind of website.

HOWEVER, Belgium’s open data law requires the gov to share any data they get with the public. And for some reason the gov maintains a DB of the train routes and schedules -- which means everyone gets the raw data as a bullshit-free CSV file (but sadly no prices, which fucks everything up as far as being able to avoid the enshitified web entirely).

Does anyone know /why/ the gov gets that data? It would be useful to know what law compels SNCB to share the info because I wonder if other data can be liberated through the same mechanism (such as bus routes, flights, rideshares, etc). My first thought was customs and immigration must have a need-to-know, but the dataset covers both directions and IIRC it only has good coverage of domestic routes not international (strange).