From an engineering standpoint they made a set of design choices with the m series chips that sacrifice easy upgradability for the benefits of ram soldered in very close to the chips that are gonna use it that smartphones, tablets and most laptops have. Before someone jumps in and says it’s possible to have replaceable ram in that same space, yes, that’s true but you’d have to pull the heatsink off every time you wanna swap it out, and for what? Almost all users never upgrade their ram and choose instead to get anew computer (this has been true forever, btw).

From a sustainability perspective, if no one is upgrading anyway and getting the ram socket off the board saves a few grams of plastic, that’s a net win. Plastic recycling is fake and made up, metal and electronic recycling are real for better or worse. Is it better to keep the 5% of devices that will ever be repaired or upgraded running or reduce the amount of plastic in the waste stream on the other 95%? Idk. But I know that apple has a recycling program for devices.