All the wire nuts I've ever put on could pretty much support my whole body weight as well as the wire itself. Given, this takes some practice, but it's certainly doable. I also almost always cover the entire thing with electrical tape, in case there's some exposed wire there I can't quite see.

And wire staples aren't that big a problem, as there's much more danger from a homeowner accidentally putting a picture frame nail through a cable than an electrician putting a staple through one.

And don't forget that mains wiring in the US is almost always required by law to be done by a licensed electrician, and usually government-inspected after the fact.