REALLY Apple has not figured out how to easily Sort between likes and dislikes of photos?

I use a keyword, NotFav, with the shortcut, x. You can use the Keyword Manager, command-K, to create the keyword and the shortcut. The shortcut will appear in the filter at the top right of the thumbnail view. If you haven't used keywords, you can learn more here:

Add keywords in Photos on Mac - Apple Support

When I get a bunch of new pictures in an album, maybe called "NEW," I make a Smart Album with the criteria ("Album" "is" "NEW") and ("Keyword" "is not" "NotFav") . Then I go through the pictures and type x when I see a picture I do not want to be a favorite. That picture gains the keyword NotFav and so will disappear, but it's still in the NEW album. Then I go back and do it again with the remaining ones until I only have the best pictures left. Then I select all and hit the "period" to make those favorites.

Now all my pictures have either a heart or a NotFav keyword. Both of these are listed in the Filter section. To double check, I have a Smart Album to find pictures that may have both, or have neither, so I can fix them.

This works very well for me.

It is more flexible, if you have several ways to organize the photos.It would be limiting, if every photo that we do not mark as a favourite would automatically be deleted.

In Photos we have four different ways of categorising the photos:

• The favourite heart ♡: we can use it mark our very best photos by clicking it and remove it be clicking it again.
• Deleting a photo from the library ⌘⌫ or ⌫ : We can delete photos completely from the library by using the "delete" command. The ⌘⌫ combination will delete the selected photos outright, independent of where we are viewing them, whether in an album or in the Library views. the ⌫ key alone will either delete the photo or remove a photo from the album, depending where we are viewing the photos.
• Removing a photo from the an album, but leaving it in the library ⌫ : When organising the photos in albums we may need to remove a photos from an album, but keep it in de library and not delete it everywhere- use ⌫
• Hiding redundant photos ⌘L: Sometimes we want to get photos out of view, that we want to keep, but do have them clutter up the library, when working with other photos. ⌘L will hide them temporarily until we unhide them again.

It is more flexible, if "Liking" and "Not Liking" are not automatically a decision about deleting or keeping a photo, at least in the way I like to organise my library.

Because you can do it by tapping the delete key in the Library and with a right click in an album.

How hard is that?