GWR should be providing new trains for all its services.
Disagree.
The age of the trains is IMHO of little importance. Much higher priorities are IMO.
Trains long enough that everyone gets a seat, except in extreme and unusual circumstances.
Reasonable comfort, decent legroom and no more 2+3 seating.
Reliably working toilets.
Reliably working air conditioning.
Generally in good condition, some old trains have been refurbished to a good standard, and some newer ones leave a lot to be desired.
New trains should not in my view be specified simply for being new !
New trains should be obtained under the following circumstances, IMHO.
1)When the existing fleet is inadequate for growing passenger numbers.
2) When new trains will "pay for themselves" by lower maintenance and other running costs.
3) When the old trains are not compliant with modern requirements, and costs of modification are excessive.
4) To standardise on one type of train in the interests of simplifying training, rostering, and maintenance. For example if a hypothetical operator had 60 IETs and 4 class 158s, it might be worth replacing the 4 odd trains with IETs to give a uniform fleet.