I think there is no way around it, good freelancers and good clients will cut the platform leaving there the naive workers and problematic clients.
They survive by making you work for cheap when you enter the platform (kind of unwritten rule to earn "reputation") but once you start commanding better fees they will kick you out under any pretext - they know professionals with good portfolios are going to leave the platform anyway.
Freelance marketplaces are a race to bottom. They have a deleterious effect on your career turning you into a low-fee/shitty-client magnet.