@atomicpoet For me it's not decentralization (of the protocol), it's the how it enables more diversity in my activity. A few years ago, it'd be fair to say that apart from maintaining a professional homepage and one for my project, almost all my online activity was on Twitter. Now it's split (by my count) about five different ways, and Mastodon is just one of those five.
But it enables me to parcel things out, post them different places, etc.