Have you seen the fairphone? It's exactly this. The first one let you replace all components without any tools. The latest one needs a screwdriver (which it comes with).
You can upgrade a fairphone 3 to a fairphone 3+ yourself just by buying the updated components. It's pretty cool! But it isn't cheap.
You can upgrade a fairphone 3 to a fairphone 3+ yourself just by buying the updated components. It's pretty cool! But it isn't cheap.
https://shop.fairphone.com/en/