I think we’ve seen how Google can kneecap it’s open source products with Android, taking more and more portions into closed source. Why won’t they take the same step with chromium if Microsoft edge and Brave become too popular?
In your example, Chrome is to Android as Chromium is to AOSP. They can not close the Chromium parts, much like they can not close the AOSP parts.
Having MS Edge and Brave becoming too popular would be akin to getting LineageOS, /e/OS to mainstream, and it is exactly my point: no matter how much that would be against Google's interests, there is nothing they can do about it.
Lineage and e are both at a disadvantage because of a lack of Google play integration which makes banking apps among others not function. People can hack around this but the OS will never end up mainstream as a result.
To do the same to chromium, all Google would need to do is make YouTube rely on some proprietary DRM that’s not in Chromium and everyone will end up switching back to chrome. Brave isn’t large enough that Google cares to swat them away, but since they control the underlying project they have ways to neuter chromium.
> People can hack around this but the OS will never end up mainstream as a result
Not people. Companies.
Microsoft and Brave are only piggy-backing on Google's resources and manpower. It's not like they can't they do it, it's more of a "why should we try to set sail now while there is a huge transatlantic ship that can carry us?".
If Google starts neutering Chromium, it's on Microsoft, Brave and all other browsers depending on it will pick up the slack.
And if they don't, that's when it makes sense to look for a Chromium-free alternative.
If Mozilla's problems were financial or lack of capacity to get the resources to work on the browser, at least you'd have a point in saying "we need to support the alternatives now". But Mozilla's problems are not financial, they are due to bad leadership. No amount of money thrown their way is going to solve it.
> Brave isn’t large enough that Google cares
Google asked Brave to testify in Congress in their favor, to say that Google is not abusing its dominance on the web. Google can not swat them away.