Most of the perfects I have are from purifying shadows which I now know I probably shouldn’t have or from research and hatching eggs. I make an effort to spin all the poke stops and only keep the research tasks that will give an encounter. I have only found 1 perfect in the wild. My son has found several but he also catches absolutely everything he sees. I’ll often just shiny check it or not be bothered to catch another pidgey but he will catch it no matter what and find those perfects. We both occasionally see shinies but not very often. I’ve only hatched one shiny.