I’ve had a very different experience. I can think of three occasions where I was able compare a hand written parser with something built using a parser generato

I’ve had a very different experience. I can think of three occasions where I was able compare a hand written parser with something built using a parser generator or similar tool. In two of those cases, the hand written code was far easier to read and modify. This kind of code can also be easier to test. Parser generators aren’t a free lunch and they vary considerably in quality.