That is not a win for open source because reducing payments is not a goal of open source. Assured continuation of availability and ownership of user's data is the explicit goal of the FOSS movement as stated by RMS. That means that it will continue to run on your hardware, and won't lock your data, and you can fix the bugs and suit it to your purpose.
RMS is on record as supporting BSD style licences for certain things because without them, proprietary software would have an even stronger stranglehold.
So it's not totally black and white, there's tactics and strategy involved. The less money going to Adobe, the less power and control they have. If they can force you to pay, they can force you to do other things. If they can't force you to pay, then they can't force other things as well.
Richard Stallman’s personal philosophy does not define the goals of open source. There are many different people contributing to it for many different reasons, and yes, having free (as in non-paid) alternatives to proprietary software is one of the most prominent ones.
> Richard Stallman’s personal philosophy does not define the goals of open source.
Richard Stallman has nothing do do with open source, and Free software was defined as Richard Stallman's personal philosophy, take it or leave it. He hasn't changed it.
I'm a complete free software advocate, but definitely only for Stallman's reasons. I have no urge to give free things to computer programmers. If I'm going to give away free stuff, I'll give to the poor. I don't have any special sympathy towards the needy computer programmer just because they share my hobby/vocation.
Money was never the issue.