Google is getting increasingly difficult to give feedback to.
The location varies by product.
Google Sheets Under help, "Help Sheets Improve"
Google Docs Under help, "Help Docs Improve"
Calendar Circle question mark top right, "Send Feedback to Google"
Gmail Circle question mark top right, "Send feedback to Google"
Google Search Very bottom of page, "Send Feedback"
Google Maps Bottom right in 4 point squint type, "Send Feedback" Unless it's a map error choose the bottom item on the menu. None of the others allow for a comment.
Most feedback allows you to include a screen shot. This will NOT include a dialog box, or some other kinds of popup boxes. E.g. the info balloon on a map pin nor will it work from all screens. E.g. Sending google feedback about the gmail settings page is difficult.
Google will not acknowledge this at all, except for certain map errors.
I also collect these in files. I have "Wishlist for Sheets" that is now 29 pages long, "Wishlist for Gmail" which is now 4 pages long. When I find a likely audience I paste chunks into it.
As far as I know, no one from Google reads their own product forums, and they certainly don't read stackexchange, even though they suggest SE for finding solutions. They do not read reddit's google groups.