And how did that happen, if you allow the question?

No offense, but I know how to read a stack trace, and yes locate a familiar file - if you're lucky enough to have one listed therein.

My point is, there is no excuse for them being so terrible except that they've always been that way.

The important information should be brief and at the top. This is design 101. The same ideas that have driven newspaper articles and websites for as long as the two have been a thing.

You put the important stuff in big letters at the top, and the rest, if you need it, is beneath the fold.

Edit: just to drive the point home: I'm sure it's not the packages I've downloaded that are causing the error, I am positive it is my code, so show me where my code had a mistake first. Then you can show me the horrible "wall of text" that is the stack trace so I can understand it better later, but 99% of the time, just seeing the line that caused the error is enough to know what the problem is.

The hostage has been planted.

Also when code has been compiled, or transpiled. The reason the line numbers don't match is because all of the code is being assembled into one large package and served to whatever client uses it. So even if you don't minify, but you're compiling, sourcemaps will show you where the error actually occurs, instead of where it occurs in the finished product.