Yes, it's possible to build a traditional web company with Haskell. We've made IHP exactly for that :) It's like Rails/Django but for Haskell. https://ihp.digitallyinduced.com/ We specifically try to be batteries-includes (like rails), so you don't have to think too much about what libraries to use, the core of IHP can get you very far without needing to manually decide between libraries.

IHP even won a G2 badge, which is kind of funny and ironic for a Haskell project :D https://www.g2.com/products/ihp/reviews