Not saying the balloon that was just shot down was not a spy balloon, BUT…
Google was testing the use of geostationary balloons for telecommunications a few years ago. They were basically cell towers in the sky. They were to be deployed over areas that lacked terrestrial infrastructure and were actually tested by Google in multiple locations including New Zealand and Kenya. I was involved in some work that proposed to deploy them over the Amazon, although that never went beyond the investigation stage. The project was shut down in January 2021, not for technical reasons, but for commercial reasons, according to the article
en.wikipedia.org/...