Cost is one factor, but what about user experience? Rich front-ends that users spend a lot of time in can save them time and the company money. Case in point, I work at a company where one team works on the front-end for customer support employees. They have to run through certain legal processes from time to time, like sending customers emails with contracts and the like, or looking up various data from various services. Their efforts have helped save these agents a lot of time, and part of that is putting more and more into a rich, clear and convenient front-end.

Of course, a lot of the effort also went to tying together various systems, replacing outdated ones, developing smarter and better chatbots and voice bots to guide users towards answers or self-service, etc.