Doesn't this "freezing concept" effectively kill the idea of background services?
If there's an app that I only need when I open and don't care for it bg service then I should be able to tell it f off. devs might think their widget phoning home everytime is worth my battery time, I might think otherwise.
Not every app needs to be a web app or use internet yet most apps nowadays do. Either you allow ALL apps to have it or you don't. You will think that devs would make apps that don't need background services. It won't happen. What will happen is that every time you open the app, you will be nagged to allow background services to run. The only thing that would stop it is for that feature to not be available at the application level.
If the user doesn't want that happening for a particular application, the user should be able to turn it off. Mobile OSes have given way too much control over to developers. Whose device is it anyway? The user's or the app developer's?
If you ask most senior citizens or simply most users of computing devices to explain what they think about "background services", most won't know what you are talking about. Just because a functionality has been present in a system for a while does not mean that everyone will know about it. Ask people about dual booting, most won't know about it. Ask most people about "SSL", most won't know about it. Ask users about the command line, most won't know about it. And so on. Even the abstract concept of a search engine (separate from the concept of Google Search) is likely to fly over the head of many people. You vastly overestimate your audience. Let's put it this way: most computing devices nowadays are mobile phones and for many people this is their first and main interaction with computation. The modern ubiquity of phones is bigger than that of personal computers by an order of magnitude imo. Personal computers were huge but mobile phones have a level of penetration PCs could never reach.
When you buy a device, you agree to the terms of service. Most manufacturers like Apple have something along the lines of "don't interfere with the proper working of the system". Freezing apps sound like it breaks the ToS.
Buying a device is less like buying a toothbrush and more like buying a tractor. You don't own it inconditially. You own it under certain terms. Those terms give the manufacturers lots of power.
Have you personally asked them? I think you'd be surprised. The #1 end user smartphone concern is around battery life, and end users, across all ages and technical sophistication are at least vaguely aware that their phones "do things" that they can't visibly see and that it's often what drains their batteries. Senior citizens aren't fools. They might not know the technical details of what exactly is happening on their phones, but they are absolutely aware of battery-draining things going on unseen in the background.
And even if they weren't aware--that doesn't address my main point: The end user should ultimately be in control of their device's function, not the app developer. If there is a conflict between what the end user wants to do and what the developer wants to limit them to, the end user should win.
You can desire all you want. Doesn't change the reality. You can't truly have control without understanding. All it means is that users will get some user defaults (and the device will function exactly as it does now) or worse, they will be compelled to change the user defaults to their detriment (and to the benefit of a third party). There's a fundamental information asymmetry. This is the source of the power imbalance and giving more "control" to users (who already struggle to understand the one they already have) won't fix it.
It's not too different from consumer protection laws. Consumers have a limited understanding of their power while companies have a wider understanding. This means that overall companies win and there needs to be a knowledgeable third party constantly watching and advocating over the interests of the consumer.
Techies have this tendency of trying to fix every problem with tech, even when it doesn't work (looking at every problem like a nail that can be hammered). You can't fix this with more tech. A better solution (by no means an optimal one) is to have public free phone tech knowledgeable advocates that people can see in person to talk about their problems and desires regarding their device.