Except chrome isn't really a "property app" so much as a "proprietary OS"; it's the platform in which ~70% of desktop users spend >10 hours a day. This is different from eg Facebook, in that FB's valueprop is being "full stack" (content + controls + ads); while Chrome's design is open-ended -running other people's websites, with other people's extensions.
The other side of the issue is tough, though: Chrome extensions are regularly purchased & have ads embedded into them ( https://superuser.com/questions/1551266/how-to-track-down-wh... ), so Google's chrome extension team (couple of ~hundred person?) is essentially held accountable by ~1 billion users to the behavior of ~10s of thousands of extensions.