I’d like to propose re-framing the stance towards libraries away from “let’s not reinvent the wheel” to “let’s only add things that help our fundamental development speed.” Adding a library for one feature helps you make that feature faster: it doesn’t necessarily help you make the next feature faster. In fact, it might make your teammate make the next feature slower. It likely made your app slower. We should consider things more holistically than just avoiding coding something that a library solves.