Don't try to compare this to rolling your own crypto. The stakes are nowhere near the same for IDs as for crypto, and the stakes are the defining feature of the "don't roll your own crypto" meme.
Yes I'm comparing it and you don't get to tell me I can't.
It's not about the stakes. It's the idea that in rolling your own, you're going to get it wrong, or otherwise do worse than existing ways that have already solved the same problem.
That applies to literally all code. So if it's not about the stakes, only experts are ever allowed to deploy code of any kind that they've written themselves.
It's not about the stakes. It's the idea that in rolling your own, you're going to get it wrong, or otherwise do worse than existing ways that have already solved the same problem.