I don't believe that Adobe is trying to extort anything from anyone. The computer industry is in a constant flux of change, operating systems continually being upgraded and enhanced. Adobe must adapt to those changes. In doing so, it sometimes becomes necessary to stop supporting older systems, and that means that some users of older systems have to decide whether or not they want to keep current. If they do then they have to modernize. And that is going to cost money. If the user doesn't want to modernize, and wants to stay with an older system, then they must decide what they are willing to sacrifice and give up to do so. It seems that you have found that crossroads and have to make that choice. Make the choice, and live with your decision. Don't blame Adobe, or Windows, or Mac, or anyone else. Technology changes, and you have to make the choice of what you want to do. It's that simple.
There's some interesting psychology at work here. It's well known - and yours is a case in point - that Apple changes the rules constantly. They drop backwards compatibility and support for legacy APIs all the time, without notice. This forces the software companies to rewrite their code just to keep up. It has to work on the new OS, right? But of course then it doesn't work on the old OS versions anymore.
Blame Apple for this. They have abandoned you; not Adobe.