For sure - I've had some good lie flat seats and perks on American cross country, and some of the jetblue mint seats are quite good. I also remember seeing a post here the other day about some very fancy domestic planes they are planning to use for people traveling to the super bowl.
My first experience with business and first class was long haul through the middle east, so the disappointment is still fresh for me a later time when I treated myself to first on a domestic flight and the only wonderful part of the experience was some juice in a glass while watching everyone else get on the plane.
Domestic first class is usually just "extra extra legroom" and some comp treats and drinks. On cross-country flights sometimes you can lay almost flat.
It's missing the showers, the beds with full linens, the 1:1 attendant, the suites... If you get a chance try first class on Qatar airways, Singapore, etc
My first experience with business and first class was long haul through the middle east, so the disappointment is still fresh for me a later time when I treated myself to first on a domestic flight and the only wonderful part of the experience was some juice in a glass while watching everyone else get on the plane.