If you spend 25 years not progressing in your career at all, there's either something very wrong with where you work, something very wrong with the work you provide or you simply don't want to progress. Take your pick. Being a junior nurse for 25 years? No need for it. There is no trust in the UK where the only jobs ever available are band 5.
I've known people go up to band 6 within 18 mths of qualifying and the fastest track i've known was qualifying to band 8a in 5 years. Those are rare cases but it can be done.
I've known a few stuck at band 5 nurses yes. Some great nurses who didn't want the extra responsibility or whatever of progression. Or they were happy where they were or scared of applying and being rejected. Fine. Hard workers, deserve a lot more pay.
Others that treated me like shit as a student and then were pissy when I overtook them in a few years (one had even written in my student leaving card, good luck but don't think you can come back in a few years and tell me what to do lol). Usually work on the same ward for decades, complain all the time, are off sick a lot, late often, are mean to younger staff, claim to have not had a piss at work since the 90s but don't seem to do very much either.
Because that's another thing about the public sector, bar a serious fuck-up it's virtually impossible to get rid of someone and new managers just inherit the 'problem staff' and it's hard to effect change when there's a culture dating back years and 'oh they've always been like that, so it's easier to just leave them to it'. Plus they were often Union reps and used that to intimidate and get their own way.
The NHS has some of the most incredible staff i've ever met but also plenty of lazy, bullying piss takers that would simply not maintain employment in the private sector. They'd be out on their ear.