A lot of what current drivers have written here resonates a lot with me as a driver.
Without doubt, career progression for drivers is limited, yes driver manager, but as has been discussed not a great move for many and probably a pay cut (especially if a driver does rest days) and more days at work. A very small number may be extremely ambitious and decided to take a drop down the pay ladder for a number of years in the hope they can progress further up the ladder later in their career in a alternative part of rail. Very few driver managers progress up the chain (some to depot manager) and laterally into ops standards etc. Some of this may change as more drivers enter the grade with degrees, which historically drivers ( and hence driver managers) generally don't have.
Pretty much anything else will be a pay cut if staying on the railway and also loss of travel facilities (in TOCs) and probably defined benefit pension if leaving the industry.
It's a shame in many ways that passenger/freight/engineering was all split at privatisation, as although driving a train is the common factor, doing EMU passenger one day and loco freight etc another would lead to a big variety in work, but not going to happen.
Without doubt, variable shift work and the extreme anti-social early starts to late finishes are the worst bit of the job. Very few industries have variable shift working, but at least in a traditional 2 or 3 shift system there is a element of consistency day to day. I am sure that my health has suffered and wonder how much it shortens life expectancy. Early shift finishes on paper look great, but often by the time you're actually finished you're so knackered you just want a kip for a bit and then that ruins the night sleep.
I really don't want this to turn into a union thread (there's plenty of them), but currently for drivers, rosters are negotiated between management and staff reps. Part of drivers terms and conditions negotiated at each company is limits and a element of consistency when drawing up rosters and the diagrams that populate them. Additional t&c allow for limits on movement when 'spare' etc in the roster. One of the most contentious points in the current dispute is the RDG's wish on behalf of TOCs and with government backing to abolish any union reps involvement in rosters and diagrams and the limits. The only potential limit would be the 'Hidden' guidelines which have been adhered to on the whole that there should be a minimum 12 hours rest before a driving turn and no more than 13 days at work before a rest day. I believe that even these 'Hidden' guidelines are not enshrined in legislation but were adopted after the Clapham disaster, but even they could be up for grabs. This is why drivers are defending their T & Cs among other things.
I have often thought about leaving the industry, but am probably institutionalised by now and I don't hate the job by any means, but boring it generally is. I've always considered it as golden handcuffs, as pay, pension & travel mean it is still a decent way to earn a crust and is some ways I'm glad that I'm nearer the end of my railway career rather the beginning.
To non - drivers , I'd never tell anyone not to go for a driver job, just be realistic in your expectations and not believe all the media and socials hype.