The browser: Chrome. could be kept closed because the LGPL allow the integration of libre libraries in closed products as long as the library itself remains "libre". In this case the library is the renering engine: Chromium.
As a counter example MacOS was built on top of decades of work on the BSD operating system and Apple is under no obligation to give the code back to the BSD project... and it doesn't.
So the most valuable company in the planet took from the community and it doesn't bother to give back.
For some of us that is unacceptabme.