As a co-founder of a software company, I have an experience of 15 teammates for 4 years. Generally, our projects need a lot of expertise like backend and frontend but in all times, the weight of our requirements are not equal. In this situation that we have full-stack developers, we can do various projects often we do heavy-backend projects and having full-stack developers can help us to find proper tasks to everyone.
In principle, the world needs more between disciplines experts and you can see it as a universal trend.