Because you can't use these tools on many occasions, they don't always do exactly what you want, and accessing them is slower than using a calculator. The devi

Because you can't use these tools on many occasions, they don't always do exactly what you want, and accessing them is slower than using a calculator. The devil is in the details. Such as being able to quickly switch to engineering notation to display values applicable in electronics. Also, I often want to do a series of calculations, for which an RPN calculator with a stack (you can see the top 7 levels) is uniquely suited.