Most jurisdictions in the US allow homeowners to self-perform electrical work. Electrical inspectors tend to be a lot more picky and thorough with homeowner performed work since homeowners are notoriously bad electricians.

I did all the wiring in my basement (except connecting to the panel), and the inspector did a cursory inspection, both rough-in and final. He looked at maybe two of the outlets (none of the lighting fixtures), and then on final just used a receptacle checker. Now as a DIYer with OCD and a fear of burning down my house, I had tried to be VERY careful, but it was the first electrical work I had done. Either I'm an electrical prodigy or he was lackadaisical.

Most of the mistakes homeowners make when doing electrical work are related to NM cable strapping (not enough straps typically), pigtails that are too short, junction boxes that arent properly secured, and inaccessible junction boxes.

He probably just checked to make sure you strapped the NM cable within 8-12” of the box (depending on if you have cable clamps or not) and then a strap every 54”. If you get the small details right they won’t be so harsh while inspecting.

If you are careful and follow the rules, it’s pretty straightforward to wire branch circuits in a house. Grounding and bonding a service entrance panelboard to ground rods/natural gas piping/water piping is not as straightforward as it seems.