Sagging doors: where to start?

[Grit dog]

All great information. Agree with @bucket diagnosis 100%.
Short answer, looking at what you got. Yes the door has been hanging on the striker for a while. Like every single truck almost.
If the pins aren’t worn out or even if they have a little slop, looks like you can get the doors up off the strikers and help the fender gap a bit by just shimming the bottom hinges on the cab side. Doesn’t take much

 

[Broken85]

Open the door, grab the bottom corner and see if it moves up and down. Keep an eye on the hinge pins when you shake it. That is where you want to start.

You can replace the hinges one at a time. Open the door, put a jack stand under the corner and take the hinge all the way off the truck one at a time. Replace the hinge pins and bushings on the tool bench and then bolt it back in and doo the other.