Yes, people do. They install solar panels and use them to generate at least some of their own power. Near future battery tech might allow them to generate all of it if they get enough sunlight, in which case this will become a genuine question to answer: how much to install and maintain the panels and batteries over their lifetime, vs expected cost of purchasing power from utilities.

In a similar manner, cloud vs self hosting is a valid consideration that changes over time. We now have docker and similar tools which make managing your own infrastructure much easier than it was ten years ago. I fully expect even better tools will come out in the future so this consideration does change over time. Maybe in another ten years there'll be almost no benefit to using the cloud (except maybe as a CDN).