Of course junior staff in a lot of disciplines are heavily put upon - they are young. I know I used to put in some epic working hours in my 20s. Right now my 22 yr old daughter is training to be an accountant on top of doing a normal job too - so she knows about hard work right now. Living and working in small room in central London, which in lockdown is less exciting than it should be.
Not just junior. Try being a middle to senior manager in the NHS (like my wife). Emails sometimes in the hundreds every day. Work 8am until about 7pm every day, although the 'working hours' are supposedly 37 a week I think) and then do an unpaid on-call rota every few weeks (either 9am Mon - 5pm Friday, or 5pm Fri - 9am Monday). Weekend On-call frequently means at least 2 conference calls on top of the normal 'help' calls that come in, both Sat and Sun. You are not allowed to have a drink during that time either - after all you might be called to go in (although that has never actually happened for her). Oh - and annual leave - she does get way more (35) than I do (25), but no opportunity to take it all - so every year at least a few days are 'lost' beyond the 5 day carry-forward limit.
A working day is calls/meetings from 8am to near 6pm then you can look at the emails. Lunch - soup snatched in a 15 minute gap. Sometimes you may have a full presentation to prepare or a business case to put together, frequently a formal tender/bid - guess when they get done? Often Sunday night, of course.
Then I look at friends who have senior professional lawyer type jobs - they are in their mid 50s and still work very long hours. No wonder one has decreed his retirement later this year and he can then get a life...kids have just grown up and gone.