Well, around here this is how and why I do it.
There are several factors of fertility.
I have lots of "fluffy butts", especially with Silkies and Cochins. Sometimes there has to be trimming done because too much fluff on males and females. Well, when I gather the eggs from each pen I write the colors on the egg. I place them in the incubator and in a few days I can see the development of each pen's egg and instantly know how well the fertility is on each pen.
I try to have enough roos in the pens with the hens to help with fertility.
I try to make sure I have younger, more energetic roosters.
So, for me it's not just to see if a male is doing his job, but rather if I can improve on several of these factors of fertility.
If the conditions are right, the eggs will be fertile, so it really is not a matter of seeing if an egg is "taking".
Also, just in case you don't know, you can crack an egg and see if the egg is fertile by looking for the bull's eye. I do this when I don't want to hatch.
I hope this answers your question.
