[fchu]

That's too simplistic and not realistic.

I'd rather go for an heuristic that's the dependency management equivalent of "Ask for forgiveness, not permission":

1.Find the best library that is good enough to solve your current needs, double-check to understand its capabilities and shortcomings (to internalize any known future needs), and code against it.

2. Invest the time to build your own stuff only when you start to see limitations in future iterations. By this time you'd also have a battle-tested understanding of both the dependency's shortcomings and your own requirements