Idea for using the betting/data or other statistics about potential train delay:

One gets back 50% if reaching the destination is delayed by more than 2h. Schedule the journey such that this is probable, making the journey 50% cheaper. Potentially with being able to define where one should be stuck waiting for the next train connected with sight seeing opportunities (such as the nice quarter near the Frankfurt main train station -- old ECB building!).

In 2019 there was a talk about data mining the DB arrival data [1] (yes, this problem is nothing new). One of the takeaways was that on some connections you can actually buy a "Sparticket" (cheaper, but only valid for a specific train), but get it upgraded to a "Flexticket" (more expensive, can take any train on the route) for free. This works because a delay of more than X minutes removes the specific train requirement and some routes are nearly always delayed by at least that threshold.

[1] https://media.ccc.de/v/36c3-10652-bahnmining_-_punktlichkeit... (German)

For international through Germany we used to get 100% back after four hour delays but they stopped doing that ... For obvious reasons. I traveled for free multiple times in the (long) past. Also fun of you wanted to get more back: if you had a first class ticket and reserved seat and had to switch trains and re-reserved you would get a free ticket with a stamp price for about 5 euro. Which you could ask back. So you got at least a coffee for free.