And if you're in the US and a healthy adult, you're probably not going to kill yourself if you take a zap at 120V/15A.
Wiring mains circuits is about craftsmanship and the ability to repeatably follow technical rules for low probability events that were nevertheless "written in blood". Tinkering with electronic circuits is not going to get you the engineering rigor you need to come at mains circuits from first principles.
You certainly can learn DIY house wiring safely as its own thing! The point is that they are just completely different skillsets, and you shouldn't be extrapolating confidence from low voltage circuits into mains wiring.
Also no, while 170 volt mains voltage (US residential peak voltage) is not likely to "kill" you, the actual risks are things like house fires from short circuits and intermittent connections. If you're doing anything where you're worried about getting "zapped", you're doing things horribly wrong in the first place.
For most household wiring tasks, turning off the circuit at the breaker box is the main safety provision. Using a wire nut properly is a bit tricky but not the worst thing in the world, and I don't trust a rushed contractor to tighten a wire nut any better than myself.
> Using a wire nut properly is a bit tricky but not the worst thing in the world, and I don't trust a rushed contractor to tighten a wire nut any better than myself.
This ties right into my point though. Low power circuits generally don't use wire nuts, and even when they might, they don't use thicker solid wires generally used for mains wiring. So you most likely learned wire nuts as their own separate skill, rather than from low voltage circuit work. My point is you've got to learn all those mains details in their own right, rather than thinking it's just like low voltage/power wiring.
(I totally agree about trusting yourself versus a rushed contractor! Emphatically yes - please do learn to DIY! My point is about the learning path to get there)
For mains it's not the 120V zap I'm particularly worried about, it's the possible fire that occurs months later while I'm asleep because of some rookie mistake I made (connection that gets loose and starts to spark or something), that endangers anyone in the structure.
If I could have all the danger upfront and while I'm actively working on it (like woodworking), and limited to just myself, I'd be much more comfortable.