All of that exists, don't by an iPhone and don't buy the latest and greatest nvidia graphics card. Buy a used 3060 for example. I am wirting this from a rooted zenfone 8, with notification light, headphone jack and on the second battery. Get a fairphone if you want to flip them in the fly.

For the smartphones I mostly agree. Even Pixels, although easily unlockable and rootable, make you jump through hoops if you want to use things like banking.

For PCs, there are still options available. Fractal have cases with no RGB and even metal side panels (as opposed to tempered glass ones) if that's your thing. Noctua and be quiet! still make non-RGB fans and coolers.

Fractal does black boxes and some more fancy looking ones

I'm with you on the black towers. Still rocking an Antec P120 on my wife's PC - "the monolith" it got nicknamed.

Check out Silverstone cases, they have a few that are understated, and make them in a variety of form factors if you wanted to do, say, a custom NAS, server or media center build.

I would trade in the black PC case for beige. Give me that 90s aesthetic again.

You can easily root any pixel phone. You can also easily buy PC parts without any RGB, and they are usually cheaper.

Fractal cases are basically black boxes with decent airflow designed to be quiet.

Plenty of phones are still rootable. Fairphones have replaceable batteries.

For the smartphone, what do you mean by software unlocked parts? For the rest I'm in total agreement.

The high end graphics card market really needs more clean RGB free stuff. My 3090's lights didn't turn on despite it functioning just fine so maybe that counts :) ?

As for case I know you had plenty of answers already, but I recently got a Corsair 4000D my latest build it's sleek and has no inbuilt RGB lighting.