Having many clients creates more room to explore ideas, algorithms, and architectures. It can also provide the inherent advantages of different languages, e.g., the binary size, speed, compatibility, etc., and act as a portal to a programming language community.
“The foundation of a client in a particular language opens and invites experimentation and innovation in that language. The base tooling around the client often snowballs into a robust ecosystem of tools and contributors in that language.”
A knock-on benefit is that having multiple clients means independent developers are in friendly competition. This competition fuels innovation and collaboration, creating solutions oriented toward diverse design goals. These can be targets like performance, security, scaling, user interfaces, etc. And over time, this brings more people into the tent — increasing the range of users and applications within a given ecosystem.