It sure needs a large enough push from one of few big companies (with their explicit backing) that can bring businesses to support other app store(s). But imho that has to happen in a way that it doesn't create a need to write and publish apps in yet another language to yet another platform. Because if businesses have to do that as well that will be a good way to ensuring it becomes a DoA effort.

I've a feeling companies like Meta, Amazon, Steam are well placed to do this (esp. Meta and Steam). But not sure it will be helpful to them in any way, besides they'd want to ensure their own control and locks.