I have heard people say this in justification of their framework, library, abstraction, whatever. The reality is that, from my experience, I can easily replace maybe 8 other JavaScript developers.

I am not saying that out of arrogance or some uniformed guess at my radical superiority. I am saying this out of experience. It isn't because I am smart or a strong programmer. This has proven true for me, because when writing vanilla JS I am the bottleneck and the delay. I am not waiting on tools, performance delays, code complexity, or anything else. If there is bad code its because I put it there and I am at fault, and so I have nothing to blame but myself. Knowing this, and I mean as a non-cognitive emotional certainty, means I can solve the problem immediately with the shortest effort necessary or it isn't getting solved ever and that changes my priority of effort. It also means not tolerating a slow shitty product since you are fully in control (at fault).

When people go through project management training I tell them there are only two kinds of problems: natural disasters and bad human decisions. When you can remove blame from the equation the distance between you and the problem/solution becomes immensely shorter.