First of all it concentrates power and wealth on the owners of the models (Microsoft, OpenAI) or the ones that provide the tools (Nvidia).
Yes, there is truth in it, that people who couldn't afford to pay someone to create art, or get consulting, can get this now to a certain extend (if they can afford internet access and pay the AI services they need). But this comes also at the price of lowering the income of the people who provided these services. They now need to compete in the business creation market and not in the market that they trained for. Not everyone can create and maintain a business with or without starting money, just from a skill point of view. Nor does everybody want to.
You are still reliant on the models trained by these companies. This training is very expensive. And yes there are ioen source models exist (thank god) but there are also closed source models that are very successfully advertised.
And self hosting requires money and skill. This means there is a lot of people who lack both and may then use closed source models.