Apple actually worked against Dropbox a few times in recent years, and added a bunch of APIs for annotating files in Finder, to stop Dropbox from monkeypatching

Apple actually worked against Dropbox a few times in recent years, and added a bunch of APIs for annotating files in Finder, to stop Dropbox from monkeypatching it. More recently Dropbox has started using a kernel extension to support its SmartSync feature, which will soon be stymied, as Apple makes it more convoluted to load third party kexts in Big Sur.