Will there be an 'App Store' moment for AI?

Many people have talked about generative AI as the next platform enabling a new wave of apps, akin to the release of the App Store. But companies like Microsoft and Google have an edge over outside app developers given their existing scale plus their access to cutting-edge models, better datasets, cost savings from better infrastructure, etc. If a generative AI app gets enough traction, they can easily copy it. And unlike Apple, model providers do not have an incentive to foster a vibrant community of third-party apps. Do you think an 'App Store'-like wave of innovation is possible with generative AI? Or will innovation at the app layer be confined to the Microsoft/Google/OpenAI walled gardens?