We should have the ability to run any code we want on hardware we own

It doesn't work. Everything from banks to Netflix and others are slowly edging out anything where they can't fully verify the chain of control to an entity they can have a legal or contractual relationship with. To be clear, this is fundamental, not incidental. You can't run your own operating system because it's not in Netflix's financial interest for you to do so. Or your banks, or your government. They all benefit from you not having control, so you can't.

This is why it's so important to defend the real principles here not just the technical artefacts of them. Netflix shouldn't be able to insist on a particular type of DRM for me to receive their service. Governments shouldn't be able to prevent me from end to end encrypting things. I should be able to opt into all this if I want more security, but it can't be mandatory. However all of these things are not technical, they are principles and rights that we have to argue for.

I think it's worth adding that this is fundamental enough to not just be a tech issue. There's a strong legal framework in almost all developed companies for regulating companies where acting in their self interest harms the consumer interest. Without which, lots of things we take for granted (electrical safety certification, usb c, splits between serviceand investment banking).

I think the key thing that's missing at the moment is that the types of restrictions OP is mentioning (DRM, blocking encryption) harm both consumer rights and economic development.

That's an argument that needs to come from people knowledgable about both the indistry, and the technology. Like a lot of the people reading this post.

Politics is a spectrum. Some claim that model is oversimplified but it's not. Here you're making a left wing argument that individual bad actors must be regulated for the good of the collective. However, left politicians would look at the situation and see the opposite. They prioritize an authoritarian safety-first victim-first mindset, in which individual freedoms are sacrificed to help the weakest. But companies like Google and Apple are already doing that. And whilst you're trying to hammer this situation into a left wing framing, the number of individuals who care about the freedom to install apps from anonymous developers is very small. Trivial, on the scale of a country. They do not represent the "consumer interest" in any meaningful way.

So if you lobbied politicians this way, Google/Apple would lobby back and they'd say, we are exactly what you always demand! We're acting proactively to protect the victims by limiting the freedoms of bad guys for the greater good. And the left would be not only highly receptive to that message, but having suddenly become aware of what is technically possible would likely demand they go much further! We already see this with left wing governments banning VPNs and DNS resolutions so they can better control the internet in order to keep this or that group safe.

Which sort of politicians care about the rights of freedom-loving minorities over the safety of the collective? Libertarian politicians do. But they are themselves in a minority, and would not be receptive to an argument framed as "we must regulate the big evil corporations for the greater good", because regulation is always about removing freedoms: in this case, the freedom to design a computing device as you see fit. They probably would be receptive to an argument of the form "it is important to be able to distribute code and communicate anonymously", but prioritizing something so few people care about is exactly why they don't tend to win elections.

So there's no direct solution in politics, but the closest approximation is to support politicians who are more libertarian than average. They won't solve the problem but they will at least not make it worse, and might be open to very targeted regulations that can be framed as protecting market competition e.g. requiring unlockable bootloaders can be framed as protecting competition in the operating systems market. Meanwhile you can try and increase the popularity of platforms that prioritize freedom over safety. In practice that means demonstrating some sort of use case that the big vendors disallow, which is valuable, morally positive and requires anonymous app distribution.

When you look at it like that, then what Google and Apple is doing does not fit this point of view. They are (extremely) powerful entities imposing themselves on the whole world.