Not exactly sell but Linux tbh. I feel like most people would agree with all the justifications I have but am too drunk to type for not using Microsoft or Apple but simply are not aware of how much these monopolies of the tech market encroach on their privacy. More people need to be aware and take action
And if more people wanted Linux, Linux laptops could actually be a thing sold in normal stores instead of being a niche item only found online. I think a lot of the casual user concerns with Linux stem from lack of OEM support. You have to worry about any particular hardware driver not being supported. Beyond that, Linux vs Windows or OS X work pretty much identical for the average casual user who just wants to browse the web.