If you read the article (or even the text in the post), it’s mostly about letting app developers test that the update doesn’t break their apps, and giving them time to fix things before the full release. Sure, some people will want to try out the new features ahead of time (and potentially report bugs to Google), but that’s only part of why they release betas.
Tory originally came from an Irish word meaning robber/outlaw. 350 years on and they seem to be attempting to live up to it.