H & M is comparable with Old Navy. Forever 21 has done well in Agora. Zara tends to be a step up in price and reputation from those places, but it’s not much better by quality.
They all rapidly mass produce cheap quality clothing using sweatshops and child labour and have since their beginnings decades ago.
It’s always been a huge and shady industry. It’s just been called “fast fashion” recently and is getting more attention.
Chinese brands like Shein take it to the next level yet, as their products are so poorly made and so cheap to purchase.
Fast Fashion, Explained