The actual decking floor will be concrete vs wood or a composite?

Tile!

A well done brushed finish is my favorite, however, you could consider stamped concrete.

I prefer brushed finish concrete for a non-slip surface. Growing up, that was the norm where we lived for pool decks and patios near water and I don't recall any problems with the texture. I've since had a variety of patio and pool deck surfaces and chose to do broom finished concrete at our new house for the pool deck. For the adjacent screened porch I chose an outdoor rated textured porcelain tile. At some point, we may tile the pool deck but for now the concrete is fine.

There is a sealer called sharkbite that you can put on polished concrete to reduce slipping if you decide to go with polished.

If your concrete guy is good a light broom finish is actually nice and pefectly acceptable for covered / uncovered.

Thanks everyone.

No drama here.

Is the concrete not on the ground?