I like this.
Having a few certifications, I want to agree that it makes things easier for someone trying it for the first time, but I have given quite a few open book exams where I wished I had prepared a lot more. So I am pretty sure that it will take just as much effort to prepare and learn as currently.
I think it is also good as the renewal is already open book and in reality, all IT support personnel will review online material before doing things if only to confirm that the functionality still exists and has not been deprecated as well as a newer better option does not exist.
In the long run, this will also contribute towards significant improvements on Microsoft Learn in terms of navigation and feedback to improve the relatively small inaccuracies that come into existence from time to time.