Banning query parameters (the stuff after the “?”) doesn’t fix the problem sadly. A site operator could provide a start_url value like https://pwa.acme.com/start/123456 where 123456 is a unique number for each user. Voila, you can be uniquely identified.
Whilst the article appears to bemoan the fact that the issue is being left to browser makers to fix, I don’t see a reasonable and effective alternative. The solution needs to be where it’s most effective. Letting site operators like Facebook et al decide how to prevent tracking is laughable. The problem of course is that Google intentionally broke the Chinese wall by releasing a browser. The only practical solution to avoiding tracking in this instance is to have the browser makers fix the problem and keep away from Chrome.