Yes, but calculating, for example leveling, item, abilities effects is veru useful.
Also I can't say you don't need to predetermine build. It's good to have a predeterminerd build in mind, you have basis and corrcting it during the mathc depending on situation.
I use www.demigoddb.com, but, sadly, it hadn't been updated for long and doesn't provide full information.
I really hope Stardock/GPG will run such a calculator.