Much has changed since the beginning of the free software movement: Most people in advanced countries now own computers — sometimes called “phones” — and use the internet with them. Non-free software still makes the users surrender control over their computing to someone else, but now there is another way to lose it: Service as a Software Substitute, or SaaSS, which means letting someone else’s server do your own computing activities.
Both non-free software and SaaSS can spy on the user, shackle the user, and even attack the user. Malware is common in services and proprietary software products because the users don’t have control over them. That’s the fundamental issue: while non-free software and SaaSS are controlled by some other entity (typically a corporation or a state), free software is controlled by its users.
Why does this control matter? Because freedom means having control over your own life.