RYO is the best way to learn, if you have the time to learn. After building one own solution one is able to assess the strengths and weaknesses of what other more experienced people built. Without the learning phase those other solutions are incomprehensible black boxes. The trick is not to skip the phase in which one researches available solutions.
> RYO is the best way to learn, if you have the time to learn
The problem is that nowadays, people roll their own solution, don’t take the time to learn (somewhat understandably, given the complexity of today’s stuff. You simply cannot learn all details about your hardware, OS, and third-party libraries anymore) but immediately deploy things in production.
Eating your own dog food can be good, but for security related stuff, it can easily be disastrous.