> The flip side to this is that just because an app is entirely local doesn't mean it will work as the software around it gets updated (OSes etc), so if a company decides to stop supporting it, that too is useless in a way.

This used to be less of a problem, when OS vendors gave more of a shit about backward compatibility. But still, even today, this doesn't seem like a major risk. OS platforms really don't change that fast. I would expect a Linux, Mac or Windows app purchased today to actually work unpatched (on a computer with the same CPU architecture) for 10, maybe 20 years. I mean, we have games from the 90s that still can be made to work on a modern Windows machine.

The most recent OS-driven rug-pull that broke software that I remember is Apple removing support for 32-bit apps. Which yes was a dick move.

The web as a platform is a different story. Browser APIs are all over the place and things get broken constantly. I honestly would not be willing to pay for a browser-based software, full stop. I just feel like web developers in general are way less serious about forward and backward compatibility, and making sure their software works on a browser that isn't "Bleeding Edge Chrome".