To each their own.
We live in a golden age of factory ballistics where you can buy off-the-shelf stuff that can be very high quality across a wide range of guns. Sometimes I have a hard time beating some of the stuff in hand loads and it can take a lot work for a load that might only work better just in my particular gun. I chrono almost all my loads--I like to use the info to cross-check predicted results from ballistics software (and vice versa). Presumably the ED/SD numbers also help confirm a node for that load in your particular barrel. I don't get too hung up on the number of shots, though I usually shoot 5 to 7 for a particular charge weight. Once I find a good group "candidate" with tight ES/SD numbers I'll shoot 3 close charge weights at the same time--looking for very close results between the 3 groups as confirmation of the likely presence of a really good node. Every once in a while I'll have excellent ES/SD numbers but the grouping itself on paper might be terrible--often that indicates to me that there is a possibility that there might problems with the gun set-up.