Hmmmm...
Well, several of the shapes are very geometrical/mechanical, unlike in the real world. Using materials with more bumpiness and then displacement might help. Like on the vertical poles. See how razor sharp those edges are?

Then your POV (straight on) also emphasizes the mechanical look. More slant to the lighting and not so flat might help. Maybe using the spectral atmosphere "aerial perspective" (smog like) and better clouds?

Distant hill look bare between the trees - maybe some bushes and/or ground cover. Also for the terrain,, exposing some rock or soil at the water line and adding a "wet" layer just above the water might help. A wet layer on the foreground float logs might also help.

The foreground deck surface is obviously tiles. Real decking would be more random and less repetitious. The 2 center float log ends are identical, should rotate one.

Using soft shadows, rather than your hard edged ones adds realism (at the cost of long render times).

Some of your surfaces lack dirt and wear/tear: inflatable boat, bobber, decking. Those need some material customization in the Function Editor.

Last, but not least, photograph or find online a photo of a similar environment and study that.

HTH