Well, feel free to spend your own time on writing such a tool and releasing it as Open Source. That would be a really cool project! Until then, don't complain that others aren't willing to donate a significant amount of their work to the public.

There is a vast gap between walled garden cloud service rent seeking and giving away software as open source. In the olden days you could buy software licenses to run it wherever you wanted.

I agree. Paying by the month for the rest of your life or they cut you off is not something I am a fan of. I feel sorry for people too young to remember that you could actually buy an app, get free bug updates and get a discount if they made some big changes on a new version that you might (or might not) want. But it was up to you when and where you ran it and it was yours forever. I have heard the arguments for why people enjoy this monthly subscription model, but my counter argument is that people did just fine before without them, so what is so different now? And I mean, in general, not that you need to use a GPU for 1 hour but don't want to buy one. I mean, for example, how Adobe products run on your computer but you rent them forever.