I do not claim to be a typical passenger, but since all the problems on the Marches and the tendency to drop trains from timetables before 22:00 there has been more value in having staff around. It makes me wonder whether there is actually a false saving in closing ticket offices.
For example the 05:36 1W13 to Manchester leaves Swansea just after a 05:28 GWR to London and requires a long wait for the 06:38. Taking the 05:28 can get you to Manchester earlier than 1W13 with a change in Bristol Parkway. Alternatively the 05:28 gets to Cardiff for a connection into any 1W13 that starts there. Authorise a ticket on those options and there is no delay repay. Follow the instruction to only use TfW and wait for the 06:38 and 9 times out of 10 it is a complete refund because the later train won't reach Manchester on time and even a minute late ticks past the 1 hour after 1W13 would have arrived. The ticket instructions are very clear, you need more than 61 minutes delay to move away from the booked operator and the 06:38 arrives Manchester 60 minutes after 1W13. Without taking the thread off topic to discuss the ins and outs it is pretty straightforward to see that the decision made at 05:25 in Swansea can save a significant amount of delay repay for even 1 passenger.
I am all for having a visible presence (and it should be visible, not hidden away in a cab or an office) but unfortunately in my experience customers can be treated very poorly at stations when asking to be re-routed; I have very rarely had a good experience. In most cases, if blanket acceptance is not in force, I have more fortune in asking permission from staff on trains (whether that be a Guard, TTI, OBM/OBS is immaterial) than at ticket offices.
The issue you describe occurs irrespective of whether staff are located within ticket offices, at the platform or neither; it's an issue the rail industry needs to address but I don't think it is affected by these proposals in any meaningful way.
If you imagine that at a busy location there is 1 passenger per hour who can be given appropriate discretion then it soon reaches the point where the ticket office pays for itself.
But that is assuming the railway has a policy of minimising delay to passengers in order to reduce Delay Repay liabilities; sadly this is all too often not the case. In any case, if this policy was in place, you'd not need staff in an office to communicate this.
I can see absolutely that the ticket office is not what it was. However, the temptation to deskill and/or totally remove staff from stations has potentially negative consequences financially.
Maybe, but does the railway have fewer passengers now than it used to do decades ago? Are ticket office times increased or reduced today compared to decades ago?
I suspect the answer is that ticket office opening hours are reduced and yet more passengers are travelling; that's certainly the case in my area.
Of course the other alternative is to have a simpler system which says all tickets have full acceptance and advances become flexible tickets as soon as the specific booked train is cancelled / removed from the timetable. It is not beyond the wit of human kind to devise fully digital systems that would simply update the ticket live when changes were made, but in the UK we are not there yet.
Feel free to create a new thread in the appropriate forum section; link to it from here if you like. I'll reply once you've made a new thread as it's a whole new topic in its own right.