I disagree with the overall substance of your argument.
Sure, if you’ve already designed something on paper and want to feed numbers in and get a part, CAD is clearly superior. I don’t work that way.
I will use (and recommend) the tools that have the least friction for me. I would not increase the time and headache to complete a project just because someone else thinks another workflow is better. I don’t need CAD because 3D printing tolerances are not that tight. Some people need/want CAD because that’s the only kind of tool they’ve used to make 3D objects, and that’s low friction for them. That’s cool too.
I’m suggesting Blender here in case someone (OP or a passer-by) hadn’t considered it, and didn’t realize that it’s up to the task of creating 3D printable objects. It definitely can, I’ve done it dozens of times, even with matching measurements against existing parts (which - it occurs to me now - is most of what I’ve done).
Also, I exclusively use Blender VSE for video editing. Mostly because it’s the best free/open-source option I’ve tried, and I don’t need to add another tool to my workflow. I never really liked the Adobe suite, and most non-adobe tools try to cosplay as them. It’s a lesser form of a thing I already didn’t like.
I only work in dumbass terrestrial systems administration, and even we do that (mostly because I pitch a fit when they try to test more than one thing at a time)