Are you working with the Online application or on the Desktop?
WIth the Desktop application, there is very little difference between the commenting facility in Microsoft 365 and that in Office 2010 and I would actually prefer the presentation of comments in the later version.
The comment facility in the Online application however is quite different.
I am not sure what you mean by "keystroke tools"? AutoCorrect works in the comment balloons in the same way that it does in the body of the document.
The one criticism that I would make about the comment facility in all versions of Office is that it is not possible to change the size of the font.