Here's a list of things that may be helpful if you're interested in data ownership and the decentralized web.
/e/Foudation: A non-profit company building a private and secure mobile OS.
privacytools.io: This is a fantastic site for finding privacy-oriented alternatives to popular centralized software.
No More Google: If you don't really care about using centralized services in general, but just want to diversify away from Google specifically, this is a great site for finding alternative apps.
r/selfhosted: One way to leap towards data ownership is to self host your own webserver and run your own internet services. That way all your data is physically on your property and you can disconnect it from the web at any time. This subreddit has tons of great resources and recommendations for going this route.
Center for Humane Technology: Tristan Harris is partially responsible for the existence of this blog. He opened my eyes to the perverse incentives of the attention economy. One good place to start would be his Time Well Spent post.