I traveled down the 'terminal commands' rabbit hole years ago.
What I found is that some of the utilities I was using, CORRECTLY, Had ZERO effect on the performance of macOS.
Seriously!!!
The command showed they completed. macOS completely ignored the changes I tried to perform. COMPLETELY!
I called Apple support, and requested to get sent to someone 'who knew the command line', and was sent to someone who said he was a programmer engineer, and had a huge history in Unix.
He lauded my drive to do what I was trying to do through the command line, but said that his experience is that the ability to change the overlying OS through the command line for what I was trying to do was 'patchy at best'. He said that what I was trying to do was 'valid' in Unix, and should even work in Mach, but macOS at that time tended to ignore some 'various' commands and results. Like I could query Mach, and see that the change happened, but macOS was looking at its own information, and it didn't support that particular function. It was an obscure ISP thing, and it's been so long, I can't remember the exact stuff I was trying to do, but he said that macOS wasn't going to do it.
So, command line is great. For what is still supported. I can imagine that the list of things that you can't change through the command line would fill several volumes in a library, so yeah, be aware that some stuff just can't be done, and it's not all 'heavy lifting'...
But have fun. Find what doesn't work. I was so frustrated as I remember. Obviously frustrated enough to call Apple support.