“Capitalism is the extraordinary belief that the nastiest of men for the nastiest of motives will somehow work together for the benefit of all.” - John Maynard Keynes
(You can also apply this one to proprietary software vs. Free software (don't say open source in my presence))
“The tyrants are only great because we are on our knees.” - Étienne de La Boétie
“Those who do not move, do not notice their chains.” - Rosa Luxemburg
Not OP, but I personally heavily dislike the confusion surrounding those terms - that is IMHO entirely self-inflicted. "Open-source" referring to FOSS as a whole, and what open-source sounds like actually being called "source available", is needlessly confusing.
I usually write FOSS since I like acronyms, but when I speak I'd say open-source. I don't see how open-source is any more confusing than free software, considering most people would immediately think "free as in beer".
Free software tells you "do whatever you want, you're free" but open source completely misses the point: it means you can read the code, but not necessarily recompile, modify and redistribute. Plus the term was invented for the confusion that would come from it.
For example, a lot of AI models like LLM's claim they are "open-source", which basically means nothing: it's far easier to say that than to claim it's a free model, because that would imply freedoms to modify, reuse, redistribute the training data, weight etc. (no AI model allows that for now, and there will probably never be one that does).