I think most people now know that you must check to see if your train is running before you set off. Essential, especially at weekends.
In the weekend context I'm someone who has used the train regularly (at least 8-10 times a year over the last 20+ years) to travel to Plymouth from my home to see family, friends etc - generally speaking I'd travel down on a Wednesday evening or Thursday morning and return on Sunday afternoon.
Recently the service has become so unreliable at weekends that I simply cannot trust
GWR▸ to get me back on a Sunday and so I either drive or get the National Express coach which is far cheaper, better value, more reliable and comfortable with a guaranteed seat.
The effect of arriving at Plymouth station mid afternoon on a Sunday, to find one's train cancelled, knowing that means waiting an hour for the next one which will be absolutely packed, if not already then from Exeter onwards, simply isn't worth repeating.
Despite all the GWR bragging, promises of a glorious future and daft advertising campaigns, my honest experience is that a consistently mediocre service has got worse, not better over the last few years and most of the regular travellers I know on that route would agree with me.
There have been too many promises made, expectations raised and then dashed etc to have much faith in the future - I hope I am proved wrong.
Until then, I'll continue with the A38/M5/M4 option at the weekend, which at least means a pleasant Sunday lunch with the family, rather than having to constantly check
RTT» to see if my train is still running.
So in the context of cancellation, the effect it's had is that GWR are at least one passenger down. I certainly wouldn't rely on services being reinstated on that route.