Besides both exercises being upper-body, I link them because they share the same gym machine.
To get the benefits of enough reps, many people (me) need the machine support for 10-15 reps/set. Fit guys and slender gals don't need it, but many of us do.
Dips, depending on form, can be either mostly tripceps or a chest+triceps exercise.
Triceps are the major arm muscle, but to balance tricep stresses it's always good to do some curls or bench presses for balance.
Dips are good, but pull-ups are one of the basic measures of physical fitness. In my first week of secondary school, we were all tested for our pullups, pushups, and running sprints - 100-yard dash.
(It's funny/sad to recall, but we were all also tested on our singing ability, math ability, and public speaking ability. Whew. As a 13 year-old nature-boy nerd, I guess, all was deeply humbling. Humbling is good for the soul, mostly.)