Not speaking for the OP, but it is a lot nicer to walk barefoot on (well-preserved) wood or decking material than most concrete. There are also, I think, some kinds of paint-on coverings that can be applied to concrete that make it nicer to look at and to walk on; I’m thinking of those epoxy or resin coatings often used for concrete garage floors to dress them up and make them easier to keep clean. If the concrete slab is not in good repair, these would require a fair amount of prep work.
A point that doesn’t seem to have been mentioned yet: if you’re painting bare wood or stucco or anything really, be sure to put down a coat of primer before the paint.
In my OP I said there would be a couple of inches clearance. The concrete slab is cracking and rather than removing it, can I just cover it? I also want to have a wing for a dog door but that is complicated to explain but let’s just say raising the patio a few inches is a benefit.
I understand the ‘wing’ for a dog door all too well, I’ve cut doggie doors into walls and doors.
You want to put the deck a ‘couple of inches’ above the patio. That, to me, suggests that you are going to put the decking on some sort of joists.
Is the concrete patio lifting and heaving?
The deck tiles I mentioned can be placed on pedestals to raise them and allow for an uneven surface.
In my case I have spiders on the ground. They don’t make it up to the deck. That’s enough for me to recommend the raised deck. Plus the old concrete in my case was really poorly done and quite rough. My stepson is a contractor specializing in stamped and colored concrete driveways and patios. He keeps offering to tear out the old one and pour a nice stone patterned patio. Nope. Spiders.
Cracking. One huge one