Movies sometimes feature gratuitous graphic violence and sex.
Scientific papers sometimes feature gratuitous graphs.
Before desktop computers it was a lot of work to produce a single graph.
Now one can produce ten graphs in an afternoon!
Why not put them all in the paper?
The paper will be longer and give the impression of being more comprehensive.
I feel that some students want to show all their graphs to show just how productive they have been.
No! Not every graph you make should be in the paper.
Analysis, synthesis, and discipline is needed.
Figures should carry the weight of the paper.
Many people, myself included, will scan the figures looking for something potentially interesting and
important, in order to make a decision as to whether or not to actually read the paper.
Figures and their captions need to be clear, comprehensible, and have significant content.
Graphs should be like text: polished and repolished. Good authors work hard at writing, editing, polishing, re-writing, and re-writing text. Some graphs should be deleted or relegated to supplementary material. Some should be combined. Some should be split in two.
Some chemistry journals now put an author produced "summary graphic" or "graphical abstract" on the journal website for each paper. I find some of these very helpful. I also feel it is unfortunate that these are usually not in the paper. I think many papers would benefit from at least one simple schematic figure that illustrates the main point, key definitions, or approaches of the paper. I reproduce an example below from a recent paper by Seth Olsen and I.