that does not mean they have to release it.
Copyleft licenses like GPL forces companies to share their code changes, at least with customers.
Which leads to more freedom for users. The goal of Free Software.
A practical example would be OpenWrt.
Fritz Adalis (npub1kp7…rszc) Andrew Zonenberg (npub1wpg…f386) Software Freedom Conservancy (npub103f…kaf3)