Yeah, until they get a foot on the door. A single foot of theirs is stronger than the whole fediverse. Google used the depend on the android open source project. Then AOSP depended on google. Then they started phasing out base apps like email, browser, gallery, sms/phone, calendar, file manager, music player, etc., in favor of proprietary google apps and made everything require google play services. Other vendors stopped using the AOSP apps as well, and made their own versions in response, up to and including entire app stores like samsung apps. Today most users only know the proprietary android experience, even the UI is proprietary (android ONE, pixel UI, MIUI, etc). Even open source enthusiasts have a hard time installing AOSP or a custom ROM because of hardware level locked bootloaders. Others have mentioned the embrace-extend-extinguish tactic and this is what it is.