We can agree to disagree. “The Software” was delivered, source included. And you as end consumer are free to redistribute and maintain as you wish.
However, I cannot see any contract law judgement that would force continuation of a subscription model on the vendor (in perpetuity!) if they do not wish to remain under contract.
Please. Climate change has been a well-lnown phenomena for a very long time. Scientists in the 19th century were warning that rising CO2 from human-caused emissions could harm the climate.
https://en.m.wikipedia.org/wiki/History_of_climate_change_science