Is Fuchsia a closed source?

It’s because of same reason. Android was originally designed for digital cameras. After that, certain updates were added in it to make it compatible with more number of devices . Resulting in such a complicated design.

Fuchsia is an open-source capability-based operating system developed by Google.

Google’s unique open-source operating system is known as Fuchsia. Google started developing Fuchsia as an experiment back in 2016.20 Eki 2021