The generous reading, which I think is mostly correct, is that consumers mostly don't directly run open source software, e.g. LibreOffice on Linux. A ton of the software they run has significant open source components but it's packaged up as a proprietary SaaS or an app store app.
SaaS is how most people use open source, which is very ironically the least open way of using software. Closed source commercial (local) software is considerably more open and offers far more privacy and freedom.
I wouldn't say that open-source SaaS is the "least open" way of using software.
If you're using a hosted service based on open source software, you know that you can leave. You can grab your data and self-host. You can move it to another host that has reused or forked the code. You can run it locally. You have options.
If you're using local closed-source software, your files might not even be usable without an Internet connection. Think Spotify (closed source, local) where even your "offline" playlists won't load if you don't allow the software to phone home once in a while.
