And for what its worth, systems like minio have emerged due to that commercial innovation. AWS has made a lot of investment in that system and will earn perpetual annuities from it, but by creating a defacto protocol we now get many choices that use its API. Its interesting because AWS never was benevolent with their S3 code, they just created a novel and rigorous offering that became worthy of emulation. Dropbox really hasn't done any equivalent contribution. If anything, the open source projects that have emerged to offer self-hosted alternatives to it are more feature-complete and extensible- such as nextcloud/owncloud, pydio, syncthing, etc.

side note: I'm filled with regret for every document that I authored on Dropbox Paper. It didn't last for long, but there was a time that it was the official wiki for a company I worked at. Its not impossible to export, but never with full-fidelity.