Do you compare the input methodes of chatsbots and websites or do you compare the current implementation? Chatsbots are new in the game and HTML is kind of old. The earliest web shops and services sucked too.
If you only type “weather” in the chat. The bot could send you an image of the forecast. If you go shopping he could show you images first and asked to filter later.
Chatbots are not always better or equal but e.g. you don’t have to register, sign in, save password because you can already identify you.