I’m not the best at level design, but I think some small foliage (like dead bushes or cactuses) could go a long way. I also think there should be a tower in the middle of the map to just fill in that big empty gap there.
You can add a temple in the middle for the players to intersect, add dead bushes or bushes, you can try to add more textures and pattern on walls and structures (flowers, ancient symbols, crosses,…), if it is abandoned you can add more tumbleweed and diminishing structures. There are actually quite a bit of things you can do to make it more alive just look at reference images. Keep on working. Goodluck!
like everyone else said, its missing small decorations and structures. Specifically, I would suggest statues. Also, as your game is a fighting game, you could add weapons on the ground (purely decorative) if its more cold-weapons. For example, a few arrows sticking out of the ground or a sword lying on the ground would look great.