I no longer live in easy reach of one, so haven't shopped there for a few years, but I've always found their clothes to be fine and good value.
I've bought clothes at just about every price point on the high street, and really, price isn't an indicator of quality.
I'm not happy with my weight at the moment, and I work in quite a dirty / sweaty role, so I don't bother shopping or buying nice clothes these days.
I mostly wear supermarket clothes, which are generally fine.
But I do have primary items that I've had for years and are still going strong.
Other than actual clothes (jeans, jumpers etc) I have vest tops that I've had for years that I wear under my work uniform.
These vest tops were, I think, £1.30 each and I've worn them on rotation, say twice per week, every week for 5 years.
Can't say fairer than that.
(As regards the ethics of the manufacturing process and labour laws etc, yes, this is something that concerns me, but Primark is no worse for it than many other shops, and a lot better than many. But yes, ideally I would have the budget to shop fully ethically and sustainably).