While freelancing platforms might have reduced profits for some designers or coders because they take fees but at the other hand they actually opened a massive market for idle freelancers and companies that required workers might be overpaying because they did not had any platform to hire workers.

I understand that they are charging fees but they are not forcing you to join them or work through them but if you do, they have all the right to take their fees because they are providing their valuable platform to both seller and the buy and they also need to pay their team who work behind the smooth working platform and also maintenance fees,etc.

I understand the frustration from some users but more good is being created by them as compared to the minor harm to some developers.