All of that is being done where appropriate. If you read the methodology of the actual papers, you will see it there. What's not getting done is said work getting reported. There are two reasons for this.
1) Most lay people, like yourself, get their science from the media. Now that can be done well and it can be done really badly, but the one thing they all have in common is that they are media in the current age, They want something attention grabbing and punchy, and there's not much grabby in describing the precise methodology of particular finding.
2) It's routine. It's as you say 101 stuff. Who reports on the 101 stuff? It's so routine and basic to scientific endeavour that it would be the equivalent of explaining how one puts on trousers every time you talked about clothing. This doesn't mean it is not done.
And to reiterate, I am not talking about stuff I read or stuff people told me, I'm talking about stuff I have actually done. I've been off the bench for some time, but my PhD is in viral epidemiology.