Comment by julianna01k

Cloud software is slightly different than conventional software. As a general rule, you don't get access to the source code, even if the hosted software is built entirely on open source software. That may not make the software proprietary, strictly speaking, but it doesn't give you all the benefits of open source. In that sense, the benefits of using the "pay for what you use" software as a service model may outweigh the disadvantage of not having access to the source code. But here's one recent project that impressed me https://audext.com/.