Because of all your explanation, Terminal should never, ever be touch by the average user. The historical reliance on terminal is the reason that Linux adoption rates have been low.

Linux is a far better system to use for most home users that windows or Mac but terminal is beyond the capabilities of 97% of people.

I have a 11 year old low-end laptop running Mint. All I did was max out the RAM and pop in a SATA SSD. It's stable, easy to use, and fast.... until I have to hit terminal. Then it's hours of looking up commands online, trying to figure out how to get something done that should have an easy GUI. I'm not a programmer by any means. I'm just cheap and don't feel like tossing out perfectly functional hardware. So I push through it until I get it working.

Yes most of the 3% of people that use the Linux can mostly use terminal easily. For the 97% of people who are not using Linux, terminal is way beyond their capabilities.