More importantly, object storage need not even exist in the cloud at all; there exist solutions to set up S3 and S3-compatible storage on-premises.
There are plenty of examples of native programs leveraging object storage, whether in the cloud, or on-premises. Consider the latest release of Microsoft Flight Simulator, which streams high-quality assets (city/building 3D models, terrain, textures, weather data, real-time NPC air traffic, etc) in real-time as the user flies over the virtual Earth[1]. The competition has distinctly worse graphical fidelity, primarily because of storage concerns.
Scientific data—especially astrophysics and telescope data—tends to be hosted on blob/object storage (albeit not necessarily on S3) because of the immense data volume involved. These include including Hubble, the Sloan Digital Sky Survey, the Transiting Exoplanet Satellite Survey (TESS), and the Kepler and K2 exoplanet missions.
[1]: https://www.techradar.com/news/microsoft-flight-simulator-20...
Disclaimer: I am an employee at cunoFS.