I think it's fair to say that 30 or even 20 years ago wiring an average new build house was very straightforward, in my early 20s I could do a 1st fix, properly too in a good day. [Without any chasing].
But there's so much more in a current new build, probably 3-4 times as many sockets for a start, multiple lights where there would have been one in kitchens, utility rooms etc as well as things like heat pumps, electric underfloor heating and then data and alarm wiring etc etc. And the modern construction methods can be a pain where you have things like triple joists to get through plus crazy amounts of insulation everywhere and every other 'trade' seems to be on a mission to make life awkward for everyone else. So I still say that to do it right isn't as easy as many think.