Definitely Instagram.
While Lemmy is slowly making a dent in my reddit participation, it doesn’t do much for other things. I’m involved in IRL politics, food, and the clubbing scene, all stuff that is almost completely absent on the fediverse, especially the American-dominated side of it.
I don’t keep anything relevant on my machine. It’s just a way to access data hosted somewhere more safe. Also files and folders are terrible ways to organize anything, even remotely like Google Drive or similar stuff. It’s Microsoft’s and Apple’s brainrot outliving the 90s. We should move forward.