That's why the better approach is: learn how to build wheels and how they work, then use off-the-shelf wheels - unless you know that you need some peculiarities that are not found on the market; only then modify those wheels or build your own.
Goldman Sachs thinks that risk management software is so core to their business that it makes sense for them to do it in-house while their competitors used off-the-shelf software. One weekend in 2008, Lehman Brothers collapsed. Figuring out your risks after such an event was something that nobody had programmed into their software. But Goldman Sachs was able to get their people to work through that weekend and know what their risks were when markets reopened on that Monday. In the year that followed, they had one of their best business years and massively outperformed their competitors.
"You think reinventing the wheel sometimes makes sense? Haha, well I guess you also think that Google and Amazon should be manufacturing their own computers then..." ...this is something that somebody might have said sarcastically 20 years ago. Well guess what. They are.
So, if you don't have the resources of Google or Amazon it may make sense to get your wheels from somebody else, right? It's called specialisation of work.
After all many wheels on wheelhub nowadays exist because someone got frustrated from their experience with using existing wheels.