The next post after yours begins to quantify some of the ugliness. It’s not necessary to take the suggestion from @davidsrsb and contemplate the permutations possible with a monstrous 100-pin microcontroller. Some microcontroller pins have not just two, but three or more possible functions so even a diminutive 18- or 20-pin microcontroller has more possible variations for its schematic symbol than a mere mortal can efficiently manage.
When I did microcontroller projects I usually crafted a schematic symbol uniquely suited to that project. I not only labeled the pins with mnemonics reflecting the pin’s usage in that particular design, but regrouped pins so that related functions were in proximity to each other on the schematic.