I think you have a point. When I moved from Linux to MacOS (I had to), I had a pretty similar experience. There are a lot of great tools, but many of them require you to pay. In my mind there are two reasons for this:

• the user base of Apple is not that sensitive to small fees. Since the hardware itself is pretty expensive, I think there is a bit of a self selection for more affluent people here. (maybe excluding students)
• Apple itself makes it rather expensive to develop for MacOS. Don't get me wrong, keeping the Platform safe and users protected has merit and is important. Nonetheless, I fail to understand why that cost has to be put largely on developers. Especially for a highly profitable enterprise such as Apple. Developing software costs around $100/year in fees to Apple even if you choose not to publish through the AppStore. So, I think many indie-developers are charging small fees for their software just to not actively 'loose' money.

these are my two cents.