I agree pretty wholeheartedly with using tried-and-true tools instead of chasing the new shiny.
I somewhat disagree, however, with the idea that a diversity of tools in use always necessarily leads to higher costs. Sure, using the right tool for each job increases the number of tools you have to maintain, but using the wrong tool for a job increases the maintenance costs of that tool while also introducing an opportunity cost from the resulting inefficiencies of using that tool for something it's not designed or optimized to do.
As an analogy, you could use a screwdriver to turn screws or to pry something apart. Sure, this is cheaper than buying an actual prybar to use for prying, and you only have to have one tool in your toolbox instead of two, but this is a surefire way to break your screwdriver in a warranty-violating way.
I somewhat disagree, however, with the idea that a diversity of tools in use always necessarily leads to higher costs. Sure, using the right tool for each job increases the number of tools you have to maintain, but using the wrong tool for a job increases the maintenance costs of that tool while also introducing an opportunity cost from the resulting inefficiencies of using that tool for something it's not designed or optimized to do.
As an analogy, you could use a screwdriver to turn screws or to pry something apart. Sure, this is cheaper than buying an actual prybar to use for prying, and you only have to have one tool in your toolbox instead of two, but this is a surefire way to break your screwdriver in a warranty-violating way.