A busy calendar and a busy mind will destroy your ability to do great things in this world. If you want to do great things—whether you’re a musician or entrepreneur or investor—you need free time and a free mind.
You might not “own” your Twitter followers (you can’t take them if you leave), but you get to leverage the platform for distribution. You could theoretically launch your own version of Twitter if you want more ownership - but it’s practically useless if there’s no one there to read your tweets.