So to ensure that a company is more likely to be customer focused, rather than shareholder focused, it’s likely a good idea to only go for companies not listed on the american stock exchanges?

Why you blaming the OS for manufacturers issues. There are still phones out there with microSD and 3.5mm. Probably also some with decent transfer stuff. Funnily enough, even if another OS took over, it won’t necessarily bring back all the features you want, since they are hardware based. And OS is software.