I suppose it's the same as asking where people live if not in apartments.
I recall working as a PHP web developer for a corporation. Although they had a front-end team, they also had a team of web designers. Front-end developers were required sooner or later. My skills as a full-stack web developer were used for a while. They were able to bring on a front end developer in the meantime, and the team currently has five front end developers.
Every piece of software, a game, an app, or a website needs a front-end. Consequently, they have a team of front-end engineers based on the needs of the firm.