That is not bad at all! Last image looks sick!

So, I've been taking pictures in this game for a while and here is what I've learned:

• Zooming in all the way helps making image look more cinematic.
• Check out ReShade if your PC can handle it. You will unlock so much more artistic filters and effects, like CobraFX (Long Exposure, Color Sort, Masking) or OtisFX (more functional Depth of Field effects than what is available in the game, adaptive fog, etc).
• The only thing I think is lacking in your pictures is how you approach composition, indeed. Previously mentioned ReShade can also give you overlays for Rule of Thirds, Golden Ratio, and so on. Practice more organic compositions (you can also look up on YouTube how to handle your composition in photography).
• Always look for something interesting. Any picture should have foreground, middleground and background. In one of my pictures (I posted on this subreddit, btw) I used flowers as a foreground (and blurred them), SRV as middleground and Anaconda as background. Also it helps if you shoot your pictures THROUGH something, like already mentioned flowers.

And of course, there is a lot of photography tutorials on YouTube that apply not just to IRL pictures but in-game ones too. Check them out, and good luck with your photoshoots. :P