Doesn't change the fact that when you try to find out "how do I record desktop audio on my Mac?", the answer is very often "use Audio Hijack", because macOS has no built-in way to record desktop audio. (Not even QuickTime's screen recorder can record desktop audio, only microphones! It's wild.)
These days, OBS is probably a decent alternative, but it's very video focused and very streaming focused, so it's not exactly great for that purpose.
My experience as a musician and huge linux nerd is: sure, it was all free, and very powerful, on linux, but I never actually made music because of the setup times, learning, hacking, and refining the systems.
Since getting a mac and paying for tools like this, the immediacy of being productive has caused me to actually make music.
it's the same with OBS - wow, what a piece of software. I spent a week going through and configuring it. They really thought of everything. Audio Hijack solved my problem in 30 seconds and made sense for my use case while doing it.
Don't get me wrong, OBS is great! It's just clearly not made for this particular purpose, and therefore not great for that purpose. If you wanted to make an app whose main purpose is to record desktop audio, it would look a hell of a lot different than OBS.
These days, OBS is probably a decent alternative, but it's very video focused and very streaming focused, so it's not exactly great for that purpose.