Mine certainly doesn't sound hollow. The phone feels solid and well-built to me, and is performing like a champ. Hope you find a phone that you can be happy with!
My Pixel 6 sounds hollow. It's apparently because they didn't use a litre of adhesive to permanently fix it in place, making it more repairable. Which is a good thing.
The user experience in the hand is important. You're going to be tapping the screen dozens or even hundreds of times a day. If that experience is actively unpleasant to you, it's a pretty big deal.