While you are not wrong, if you have a decent language you will discover all the useful algorithms are already in your standard library and so it isn't a worry. Your code should mostly look like apply this existing algorithm to some new data structure.
I don't disagree with you at all on this. However you may need to combine several to get to an end result. And if that happens a few times in a codebase, well makes sense to factor that into a library.
