Reimagined Fireflies

The main idea is fireflies are most abundant in new untouched chunks. If there is a way to do a quick analysis to see if a large area around the player is altered from its initial generation, you can lessen the density of fireflies. Perhaps removing spawning entirely if there are little plant based blocks near the player's Y level. I'm assuming one of the reasons fireflies were not implemented is likely performance issues. In addition to limiting spawning like mentioned above, just make them a particle instead of a mob. I don't think players need to interact with them as cool as that would be. But this would also avoid encouraging children from catching them. I think this will mirror reality in that it is more rare to see fireflies now and can bring awareness to why. If a player wants to keep them in an area, they would need to cultivate/terraform instead of build normal structures and bases. Perhaps this would entice the community to have areas in their world they would beautify and consider a reservation of sorts.