3DPrinting

Also tinkercad. It's basic but honestly it works for most stuff I make for things around the house.

Fusion 360 is free for non commercial use.

Try freecad as a flatpak maybe ? Doesn't crash for me unless I do something stupid with fillets. It's harder, tougher to use than paid options but you own what you make at the end.

Blender has addons for parametric workflows. Actually, there's plugins to do anything you want.

I recently looked into (affordable) Linux-CAD programs and stumbled upon VariCAD, which, checking their presentation, appeared pretty complete. Saying that I would just make a decision after throwing a serious project, multiple parts, workgroups, parameters and technical drawing generation, on it. Maybe someone can comment on it?

I personally like OpenSCAD (with VSCode not with the built-in editor)

I liked TinkerCAD.

You can save files in fusion 360 locally. It's just not the main way the program encourages which sucks.

I think you have to like export instead pf save but you do get a .f3d file which is the same as what gets saved to the cloud.

Onshape would be ubiquity. Easy to use, flash, has all the good bits, ripe to screw the customer at any moment once enough lock in is gained.

Fusion is easiest to get going for 'serious' projects as a beginner.
I will use it while I can, or until an equal alternative is available. Nothing lasts forever.

I will be blunt. If you are as bad at math and spatial reasoning as you say, then CAD probably isn't for you. You will always find it difficult and unrewarding. Design and engineering require a mindset you might not have.

As far as "cheap and easy and professional" CAD they ALL require effort to learn and money to gain entry for commercial versions. CAD is a skill and skills require effort to acquire. And it sounds as if you have no desire to put in very much effort.

For a CAD program to meet your want of cheap and simple, (professional means a lot of money and takes more than a few minutes of effort), look at TinkerCAD. It's free and simple enough that I teach that to 5th and 6th grade students well enough for them to make simple objects. Ain't nothing wrong with starting there and learning how to think about design and CAD before you might try and step into more demanding software.

I tried using FreeCAD 5 or 10 years ago, and it was painful. I had access to Inventor, so I used that for the limited work I was doing. Later, I heard of some build/pack/whatever that removed a lot of pain from the FreeCAD workflow, but I can't remember what it was called and I wasn't doing CAD work any more. Trying to find that led me to this, though:

Ondsel ES Look

Also, I found a video on YouTube that appears to go through the same steps. Here it is.

I'm not sure it that will solve your problems, but the 20 minute video should answer that question for you.

I use alibre, it’s a one time purchase

RS Design Spark?

I haven't used it in a few years but I remember it being alright for hobby stuff.

Solidworks has a cheap maker version. You can save locally. It's always been shit, so it can't get enshittified /s.

I got a 3d printer about a year ago and looked into CAD software and came to the exact same conclusion you just did. I ended up using Plasticity. I thiink I paid $150 for a year of updates. But there are still two major drawbacks: first is it's not parametric, as you said, but more importantly you can't import stls and edit them. You can export stls, but you have to make them from scratch. You can technically import an stl but it's impossible to edit. Oftentimes I find a design online but I want to tweak it to my purposes but I can't do that.

I'd love it if Free CAD had a better UI. It's just so frustrating and hideous to use.

FreeCAD: Pros: free, open source. Cons: workflow as rough as sandpaper, constantly crashes.

It has a learning curve (like all software), yes. But I cannot confirm the crashes.