For me it's mostly the freedom and potential for customization and personalization. I like being able to install almost any app I want, being able to use 3rd party hardware like cables, bluetooth devices, etc. Not saying you can't do any of that on Apple devices but it just doesn't feel as free. I also don't feel like I'm rewarding the questionable choices Apple does with their devices, like making it difficult to repair yourself. Their phones don't feel like they're truly mine.