I meant both. What do you sync with if no central server (main client)? Anything else is unreliable, on/off all the time. And some simpler workflows don't need native apps.
I think that this is much superior to using fake apps that live on some web server. It comes with great drawbacks even when it is on the web server of the app manufacturer. Ten times more pain if I have to host it myself.
Self hosting is an unsurpassable mountain for 99% of people who need to use computers. The risk to security and data loss is much higher than from syncing your apps through iCloud or through the app manufacturer.