I think Primark is the McDonalds of clothing retail - it's ethical standards are probably better than most, but it gets more scrutiny tbecause it is successful.
Primark ARE worse than most for marketing things that are just for this season. Their kids clothes, bedding, even underpands are covered in the movie release characters of the moment (M&S have started doing this too) the idea being that in a few months it'll be a new "in" character they'll all want.
Their adult clothes are very seasonal and "now". Their winter stuff all has Christmassy shite on them so looks silly if you wear it on a chilly summers evening.
Peacocks is MUCH better in both adults and kids for basics you can wear all year round that wont date as much as Primark. Their ethics are worse than Primark BUT you dont need to keep buying and replacing.
Eg If I want a warm cardie I want one I can wear any season, dress up or down, and keep wearing until it dies basically. If I go to primark itll have this seasons cut out, a seasonal pattern or some novely harrypotter/disney shite on it so I couldnt dress it up or down.
Peacocks at least will do me ONE plain cardie thatll do me all year and go okay with most outfits.
So I buy from Peacocks knowing it scores worse than Primark on ethics, but also knowing that I will be buying less & less often
H&M used to be good for plain basics that washed well & lasted for years. Not any more.
Its difficult in that paying more doesnt get you better ethics these days. Even Rigby&Peller have started using crappy fabrics that dont last now!