> Sometimes you have to find the limit of your software/hardware.

The point is that there does seem to be a software limit, but there shouldn't need to be a particular limit there. There's certainly not a hardware limit, since an iPad can run circles around almost all of the computers of the era when LaTeX was written. Unless you believe that the TeX system represents an almost magical, once-in-a-lifetime, impossible to replicate achievement in software engineering, there's shouldn't be a software limit either, but the code base is so complicated that there does seem to be one.