Ideally, though, we wouldn't have to all reimplement the wheel the n+1th time every time. The great power of software is that something can be written once and used over and over again, unlike the way each building needs to be built from the ground, each dinner has to be cooked from the ingredients every day etc.

To give up this kind of modularity and relying on other software engineers' work would throw the baby out with the bathwater.

Sure you need to apply judgement about whether a library seems legit, but the other end of the spectrum is the not-invented-here attitude, which is also bad.