There’s two categories of disabling things.
One would be something like always on display or optimized battery charging. These are things that came with the phone and Apple intended the phone to be used with. I mostly agree with you on this point because I try to use a device as its intended because that’s the most frustration free way to do it.
Background, app, refresh or location permissions on apps are totally different. These are restrictions on apps that app developers had intentions for. This has nothing to do with Apple. A good example would be Facebook. The developer of that app has designed it to gather your information and sell it to advertisers. Having it use your location and run in the background the app will do that effectively. I don’t think it’s bad if you want this but you should always consider this as a choice not just it’s meant to be that way thing.
I just used Facebook as example because so many people have it. There are multiple apps that fall into this category of running in the background just to gather information for advertising purposes. I don’t think it’s bad to disable this to save some battery.
I’m not trying to tell you how to set up your iPhone obviously because it’s your iPhone and you need to have it the way you want it. I’m just saying maybe look at it a little bit differently 😄