That's how it's supposed to work. .
Says who?
Sorry but I have to agree with
@221129 that your post contains several inaccuracies.
If you read
this post about timing loads by
@D6700 you will understand that the 'top speeds' and 'what type of train is operating the service' are not necessarily the same as the timing load displayed on open data websites, such as Open Train Times, RealTimeTrains, etc.
Yes it purports to say which trains are booked to be 'driver only operated' but this doesn't mean much: an SWT inner-suburban Guard wont be able to sell you a ticket, while a DOO train may well have an OBM, OBS or TTI who can.
Also Chiltern services are DOO south of Banbury (except for loco hauled trains) but if you relied on RealTimeTrains you'd think they had a Guard throughout (as well as thinking they were operated by a Class 158!)
As for catering... last time I got an HST, open data sites said it had catering, an announcement even said refreshments will be served at your seat. Yet I knew it wouldn't as JourneyCheck said due to staff shortages there would be no trolley beyond Birmingham.
The relevant accurate data often does exist but is not always available in open data format.