Again, this is very bad news.
As with the Consumer Rights Act and previous to that, allowing cash refunds for delays etc - customers really don't realise that this all costs FAR more in the long term.
In response to being forced to refund in cash (and other factors), the majority of Train Operating Companies (TOCs) amended their unregulated Advance fare products, removing the cheapest tiers or severely restricting the number available. Some TOCs amended their regulated Off Peak fares, not through fare increases, but by applying the very maximum time restrictions permitted by regulation, resulting in customers having to now purchase a higher priced Anytime (peak) fare.
The Consumer Rights Act has made the situation far worse - it's early days yet, but expect to see things like withdrawal of catering, seat reservations, possibly first class accommodation on borderline or low profit margin services - because if they don't provide (or advertise) a particular service, customers can't claim when it isn't there! This results in the QUALITY of the service being degraded.
As for the delay compensation - all that TOCs will do is artificially increase journey times. They'll add longer dwell time at stations, pad out journey times, if a journey can be done in 10 minutes, they'll schedule it for 15, maybe 20. If a train is running 10 minutes late, it will then magically arrive early because the advertised timetable is padded out. This will result in the customer being shown artificially higher journey lengths, (which can affect what onward connections are offered etc).
This is most evident with CrossCountry. The 06:01 Glasgow to Plymouth currently has around 40 minutes extra incorporated for "performance", AS WELL as long dwell times at stations, for example, this one sits at Edinburgh (6 minutes), Newcastle (9 minutes), Birmingham (13 minutes), and 2-5 minutes at every other station. If the TOC and passenger wasn't motivated by money/compensation - just think how much quicker this service could be!
Finally, Rail franchises are obviously commercial ventures awarded by the government. A TOC will obviously have an idea of what profit/return it needs to make to be viable. The reality is that all companies interested in rail bidding will want a very similar return on their investment. If the government is telling them to pay out compensation after 15 minutes, the TOCs will just reduce how much they pay for the franchise in the first place, (by £millions), which results in less money being returned to the taxpayer - same with the CRA.
(For info, a Train Operator normally only makes a single low- digit percentage profit).