It is (and probably always will be) a very group-local cultural thing. So in the end vote with your feet remains the only option.

I can speak only for German universities, which in recent years have established quite a number of structural components to prevent misconduct and exploitation of young researchers. From mandatory letter-of-intents regarding supervision over formal documentation of the process. From stronger regulation regarding contract periods up to PhD assemblies on the university level.

With very limited success.

• Most measures first and foremost just increase bureaucracy. The Professors who have always treated their PhD students and post docs well, lose flexibility and have to spend a lot of additional time in dealing with administrative regulations. Those who have always behaved like a*holes, still do so. They stress the regulations as far as possible and find creative ways to weasel around them – despite the additional paper work, the actual situation for their subordinates has only marginally improved, if at all.
• PhD assemblies / unions are a nice idea, but also a hopeless attempt for many reasons. Because the situation and environment is extremely different among disciplines and groups already at the university level, there is little to fight for that realistically can improve the situation for a majority of young researchers. Furthermore, it turned out as extremely difficult to find representatives who want to do the job: During the 3 to 6 years of a PhD, you have lots of other things to do. It would take at least 3 years to be able to understand university politics and even longer to influence it – and then you are already out. How should that possibly work better on a nation-wide or even european level?
• The only measure I personally consider as partly successful is the establishment of formal ombudspeople for young researchers that have difficulties with their supervisors. I have seen several times that consulting the ombudsperson helps to find individual solutions in cases of misconduct (and sometimes the solution is to quit). But it is a measure for individual solutions and not general regulations – and, honestly, I think that is the reason for its success.

So while I strongly sympathise with your intent, the only advice I have: As you progress with your career, establish and live you own positive culture of treating your subordinates well. Tell you colleagues about it, fight for it as a criterion in hiring committees, and show the world that such culture does not harm the success of a research group.

It is (and probably always will be) a very group-local cultural thing. So in the end vote with your feet remains the only option.

I can speak only for German universities, which in recent years have established quite a number of structural components to prevent misconduct and exploitation of young researchers. From mandatory letter-of-intents regarding supervision over formal documentation of the process. From stronger regulation regarding contract periods up to PhD assemblies on the university level.

With very limited success.

• Most measures first and foremost just increase bureaucracy. The Professors who have always treated their PhD students and post docs well, lose flexibility and have to spend a lot of additional time in dealing with administrative regulations. Those who have always behaved like a*holes, still do so. They stress the regulations as far as possible and find creative ways to weasel around them – despite the additional paper work, the actual situation for their subordinates has only marginally improved, if at all.
• PhD assemblies / unions are a nice idea, but also a hopeless attempt for many reasons. Because the situation and environment is extremely different among disciplines and groups already at the university level, there is little to fight for that realistically can improve the situation for a majority of young researchers. Furthermore, it turned out to be extremely difficult to find representatives who want to do the job: During the 3 to 6 years of a PhD, you have lots of other things to do. It would take at least 3 years to be able to understand university politics and even longer to influence it – and then you are already out. How should that possibly work better on a nation-wide or even european level?
• The only measure I personally consider as partly successful is the establishment of formal ombudspeople for young researchers that have difficulties with their supervisors. I have seen several times that consulting the ombudsperson helps to find individual solutions in cases of misconduct (and sometimes the solution is to quit). But it is a measure for individual solutions and not general regulations – and, honestly, I think that is the reason for its success.

So while I strongly sympathise with your intent, the only advice I have: As you progress with your career, establish and live your own positive culture of treating your subordinates well. Tell you colleagues about it, fight for it as a criterion in hiring committees, and show the world that such culture does not harm the success of a research group.