The big companies have all the technical resources, and profoundly strong motivation, to apply their own malware and harm the user.

You do NOT check and/or balance big companies by allowing them the freedom to tinker alongside the little guy. They will wrest the machines to their purposes every time, and they are Not Happy about obstacles in their path.

Having checks and balances on big companies is a very good argument but it points the opposite direction from how you're seeing it…