Not always true, my last job had one director who worked 100% remote. She had multiple years of process knowledge she chose to share only when specifically needed to answer a question in a meeting or email. Much of this was critical information like "last year we published this report this way, but we promised to change the format this year." Even better, "we agreed not to change for 3 years but we're doing a ground-up rebuild in 2018."
A significant subset of my job for a year and a half was figuring out how to maximize the number of answers I could get from her, and recording them in the team wiki.