If you add or put too much butter in a pie crust the excess butter will leak out of the pie crust while you're cooking it.
When that happens the pie crust may not turn out good enough and may not cook properly because it may be too soggy from the butter.
Other than that the pie will still be okay to eat even with too much butter in the pie crust but it won't be as good to eat.
When making pie crust the proper amount of butter to add to your homemade pie crust is 6 eight ounce sticks of butter.
That seems like a lot of butter as well but it does take quite a bit of butter to make pie crust to perfection but you just don't want to add too much butter.