Software only makes sense in the context of the non-tech world, specifically the behavior of humans.

Despite the fact that only large corporate interests can maintain a browser, that monopoly exists because of a careful balance where developers contribute free labor to the project. Also Google's open-source initiatives still have some developer goodwill.

If Google close-sourced Chromium, they would definitely suffer repercussions. They would anger most programmers and hackers. Say goodbye to bug bounties. Say goodbye to free labor. Say hello to Microsoft taking the opportunity to fork Chromium and make Google look even worse.