The game should look like a normal Mario game at a minimum. It should use its additional color palette available in HDR to look better, and the additional brightness to make make effects pop as you describe.
The problem is that’s not what it’s doing. Some things pop better, but it’s not because they’re using extra colors. It may be a little brightness, but mostly it’s that everything else just got toned down so it looks kinda washed out.
If they did nothing but use the expanded color palette and did not use the additional brightness at all I would be a lot happier than with what we have right now.
I haven’t turned it back to SDR mode but I’m legitimately considering it. Because I suspect the game looks better that way.