Notes being “just notes” doesn’t gel for me with the idea of a second brain. Knowing when you first came up with an idea or created a connection is super useful data. Even things like “when did I read that article or read that book” is handy to know - and the note creation date gives you that info.
Consider the task of wanting to review notes you created more than 6 months ago, so you can see if there’s any new sparks of insight - hard to do if you don’t know when you created a note 