I don't actually care all that much and I like my luxuries. Do I "need" the Google account? No. Do I want to tell every person and business currently using it that I've changed email? Also no, that's a huge amount of work. Likewise for facebook, which is now down to once-a-day-ish use for coordination with a specific group of people whom I do not want to do the work of moving all of them off Facebook too.