“Through WEI, Google aims to help websites weed out bots by verifying that the visitors on their domains are actual users.”
In other words, if this gets implemented it is likely that Youtube will block anything that doesn’t look like a “real browser” (i.e. Chrome), so no videos in alternative apps anymore.
If you want to continue using any of them, you should probably uninstall any Chrome-based browser now: https://techreport.com/news/google-tries-to-defend-its-web-environment-integrity-as-critics-slam-it-as-dangerous/
In other words, if this gets implemented it is likely that Youtube will block anything that doesn’t look like a “real browser” (i.e. Chrome), so no videos in alternative apps anymore.