Right. But this is the choice, isn't it?
I don't know if you can really get away without learning general things about CAD systems if you want to make complex things, because those general things are so influential on the existence and design of real world objects.
It's like saying "but I don't really want to learn about different programming languages or software design, because I only want to write apps for iPhone."
If you want to make very simple objects and not learn deeper concepts, use TinkerCAD. It's fine. Weirdly competent in places; people pull off crazy stuff. It uses a simple physical world model.
Beyond that, you need more abstract tools. Ultimately you have to decide whether you want to exist within the (shifting) free plan limitations of a commercial cloud package, spend money on something like Alibre Atom3D, pay the cloud firms, or use something open source.
I'm not sure if it should be surprising that the open source systems are more of a commitment.
FreeCAD (main branch) has one fundamental limitation which is being mitigated -- the topological naming issues -- and some smaller issues to do with fillets/chamfers, but apart from that is a disorganised-but-competent, open source workbench-based system.
And the tradeoffs are not straightforward. This is less like Photoshop vs GIMP and more like ArcGIS vs QGIS. Is ArcGIS initially more coherent? Yes, allegedly. Is it universally more powerful? No.
FreeCAD is really a lot like QGIS, IMO.
You can learn QGIS, and when you learn it, you might decide that the freedoms and flexibility it offers are worth the pain. Or you might front up the cash for ArcGIS.