Pro: Your drawers are neater now.
Con: You just spent maybe 100x of the time and effort you would have spent if you had just left your drawer messy, and had to search through it.
My back of the napkin math is that you go into an average drawer once a week, and mess makes it take five seconds longer to find something than in a clean drawer. Assuming you live 20 years before the drawer falls apart, you move, etc. that's roughly 20 * 50 * 5 = 5,000 seconds.
Now, read the article and tell me what multiple of 5,000 seconds the OP put into all that custom foam.
If every time I open that drawer I'm a little frustrated, a little flustered, a little stressed, that's not just 5 seconds of "lost time" its a little bit of damage to my mood.
On the other hand, if every time I open the drawer it's all neat and organized and I can find the thing I'm looking for right away and I'm reminded of the good job I did building the organizers, that's a nice little micro-boost to my mood.
And maybe the time and effort spent figuring this out and building it and blogging about it was fun! Like a fun little hobby.
Everybody has a different temperament and different priorities, etc. Someone may look at this and think "what a waste of time". Personally, I kind of like projects like this that add a little extra satisfaction or polish to something I interact with freqently.
Cut the same angle on the top inside and bottom outside and you can stack shallow foamcore bins in deeper drawers. Lots of other handy uses for an adjustable bevel cutter and foamcore boards.
My favorite activity I ever did with foamcore was to make a to-scale layout of an apartment my wife and I were moving into so that we could experiment with simple to-scale rectangles as stand-ins for furniture to figure out our layout.
What a wonderful material!
Seems the calculator is designed for a "collection of boxes", which I guess is a start, but when I hear "organizer" a collection of separate boxes ain't what I want. The most significant factor of making one's own is that it's 105% customized to the need, no more no less. That means usually a lot of thought between "target place bounding box" vs "bounding boxes of things the holder shall hold".
For "organize a drawer, quickly!" I got myself a couple of sets of "modular" boxes - they have little tabs on their sides so one can snap them together like lego.