Well Junior Doctors are a case apart, so difficult to compare them doing a highly skilled vocational job (which has always had odd hours) to others grinding away relentlessly and being treated as units of production.
ironic that its only been the Eu with working time directives and similar initiatives that has actually attempted and succeeded in improving working conditions for the "ordinary person".
Ironic also that you realise that it takes concerted action to tackle the power of multi nationals (though many of the ****ty working conditions are actually with firms that are solely based in the UK, operate only in the Uk and owned or run by UK people! Again the EU has taken action on both working conditions and tax laws, one of the main things that the ultra hard brexiteers want is t be free of that regulation so they can impose even lower wages and harsher working conditions in order to increase their profits. Your correct that is what a section of the right wing "libertarian" faction of society have been aiming for for years and they are the prime movers behind Brexit!
Whilst the Eu isn't perfect it certainly provides more protection than a Brexit Uk will do - any concerted action would have to involve more than just european countries - no sign that China, India, the Us or Brazil are moving towards that direction so doomed to failure I'd say.
What the Uk could do, but hasn't is remove the tax breaks for very wealthy individuals who are so called ex pats and remove their influence over affairs through lobbying and the media. It could also be more stringent over money laundering, the amount of dirty money sloshing around from very dubious sources in the UK is appalling, but to that would upset a lot of people who ride that gravy train.
I doubt any party that promised to derail the corporate gravy train would even win many seats, that is what Corbyn (for all his faults as a leader) wants to do, and look how the right wing owned media and the current PM continually repeat how such a move would be disastrous for the country! Mind you it has ever been thus, the Sun which is apparently read by over 4 million people (most whom are no doubt "ordinary people") has a history of savagely attacking any hint of this - remember the howl of outrage when Miliband suggested capping energy prices?
We have a society where people will put up with absolute ****e IF they believe that there is even a million to one chance that one day they will get rich and join the exclusive club and be able to look down on the unfortunates they used to be part of.