No, anonymous edits are not useful.
If someone can't be bothered to register an account (with anonymity! they can be user137103820382), they are unlikely to care about the well-being of the site. Moreover, they are almost certainly unaware of the site's culture and policies.
Most every anonymous edit I've seen has been vandalism. And the few that were good-intentioned were things that should be rejected as too minor, or things that too drastically deviated from the author's intention.
This kind of noise is detrimental to the site. Especially because poor edits do leak through the review. We have a number of users who auto-approve every edit they review, and my own experiences tell me careful reviewers are outnumbered by the careless on the site (I've had to reverse a number of harmful edits to my own posts -- edits that were approved so fast I never even saw them pending.)