I call this enshittification, and it is a seemingly inevitable consequence arising from the combination of the ease of changing how a platform allocates value, combined with the nature of a 'two-sided market,' where a platform sits between buyers and sellers, hold each hostage to the other, raking off an ever-larger share of the value that passes between them. When a platform starts, it needs users, so it makes itself valuable to users.
Think of Amazon: For many years, it operated at a loss, using its access to the capital markets to subsidize everything you bought. It sold goods below cost and shipped them below cost. It operated a clean and useful search. If you searched for a product, Amazon tried its damndest to put it at the top of the search results. This was a hell of a good deal for Amazon's customers. Lots of us piled in, and lots of brick-and-mortar retailers withered and died, making it hard to go elsewher