The original point being debated is the idea that you don't 'own your own phone', and the answer is that nobody is preventing you from owning your own phone, and such phones are available, but we also have the option to choose a phone where someone else controls the software if we think that gives us a better experience.

What you are proposing is government intervention to take that right away from people - to limit their choices.

We currently have multiple different options with different levels of corporate control, and the most popular operating system currently allows alternative app stores to be installed.

Your position is to limit the allowable contracts between both consumers and device makers and is strictly anti-market. Since the proposed remedy is already enjoyed by the majority of consumers, there is absolutely no justification for such a position.