The only known method is to revert to a previous release of Word.
In this Microsoft Answers thread uber-MVP Doug Robbins writes:
This is the procedure for reverting to an earlier version of Office,
which is the only way to get rid of the debacle that is the Modern
Comments:
https://support.microsoft.com/en-us/topic/how-to-revert-to-an-earlier-version-of-office-2bd5c457-a917-d57e-35a1-f709e3dda841
The Word Product Team have been made aware of the issues and hopefully
something will be done about it.
You would likely have to roll back to releases prior to April 2021. Even if you do, though, you cannot know what will be displayed on other computers. You could send a pdf with your email that has the numbered comments.
I know that the display you show was what was present in Word 2010 and likely 2013.
Do use the Feedback mechanisms in Word to let the Product Development team know what you think of this gem. See the comment to your question which includes links to two UserVoice requests to which you can add a vote.
Note: My knowledge is not inside knowledge but comes from working on forums like this one. To reach those who may have more knowledge than I do, post a discussion on the Microsoft Answers site as a cross-post. First, though, for cross-posting etiquette, please read: A Message to Forum Cross-Posters.