I think there needs to be a national overhaul of bus ticketing to simplify it and make it easier to be automatically capped and charged the right amount. There are now several capping schemes that work differently, making it ever more complicated when traveling. Single tickets tend to be expensive, but annual reasonably cheap. Why can't I pay a set amount monthly or annually and be able to travel anywhere in the country? I think this would be a key thing if we as a country are to discourage car use.
There are many pain points with plusbus:
* Variability of coverage
* Long list of exceptions that you have to study for each area, and inconsistency
* Having to switch to local ticketing if staying for a few days rather than being able to continue to use plusbus at day a higher rate. This can get complicated especially if multiple operators in the area and no cross operator ticketing other than plusbus
* No barcode or smart card ticketing, I suspect this could solve some of the validity issues people have with drivers. It would also open up the option for people buying tickets online and not needing go to a station to get them first. I know it's in the world, but taking too long. Most buses can now read both smart cards and barcodes (Edinburgh's Lothian Buses being a notable exception regarding barcodes)
* Knowing if it's cheaper to buy plusbus or operator tickets - many operators don't provide any details of the cost of single tickets, especially if stages involved, day tickets more likely to be available.
* Drivers not knowing about plusbus schemes intermittently
* Having to know at the point of buying the train tickets whether you'll need the plusbus (granted can show the ticket to a guard or ticket office, but that's a pain and I once had a guard fail to issue the right ticket and the Ipswich ticket office has to issue a different one - Ipswich has an odd additional rail extension ticket that can get you to the town centre or hospital in addition to plusbus).
The people on this forum will persist with issues like this. The general public won't, one bad experience and they'll give up and not try it again. Is it any wonder why public transport use is so low in this country compared to people jumping in their metal boxes on wheels?