so
there's been several attempts at modular or repairable smartphones, which usually fall flat due to being from some brand nobody has heard of, being complex and expensive to produce, and having lackluster specs for the price, on top of only being available in some highly specific countries
but i think i know one possible way to bring those to the mainstream
first off, lets be real, the amount of people who are going to actually care about upgrading their phone even if it's as easy as plugging in a thing is going to be tiny; most people aren't going to give a shit no matter what you do, so trying to pitch the idea for example to investors or to some large manufacturer already falls flat there; there's nothing in it for them
but what if we instead take a page from the laptop industry's book? say, you want a Thinkpad T480
you can get a T480 in a whole pile of configurations, there's several CPU options, screen options, storage configurations, etc.; yet they all share most of the components, including the casing, batteries, most of the motherboard, cooling, keyboard, etc. you get the idea
pitch it to some phone manufacturer as reducing costs for them rather than for the customer
now, lets say for example, idk, Sony, wants to sell a new Xperia phone, call it the ZM10 for example, they can get a whole phone line out of the single design
say, want a budget phone? make a ZM1 with the same frame and mainboard layout, and as many shared parts as possible, but use a plastic back panel, a lower resolution display panel, and only a single camera sensor
now, you also want a top of the line model? ZM100, with a titanium back panel, more camera sensors, higher res screen, but still using the same mainboard layout for example, such that you can share parts like the wireless components, buttons, microphone and speakers, charging connector, potentially even battery
the end customer doesn't even need to know that they share so many parts, the enthusiasts who are going to try repairing and upgrading the thing would try to do it anyways, as i can say as someone with a Very Normalᵀᴹ Oneplus 6
that way the manufacturer only needs to stock a limited number of parts, and can use mostly the same machinery, and won't need to train employees as much, saving costs in design, manufacturing, and logistics