Sounds very much like HarmonyOS. I was just in a Huawei Store and I think from a UI/UX perspective, despite being quite new, it's incredibly slick and leaps ahead in great design and integration within the HarmonyOS ecosystem. Even saw it being used as Laptop OS and Mobile, the convergence is quite applaudable.

The kindest was that the store's staff advised against buying the device as it's quite painful to use it with Google's apk & blobs, because it drains more battery than when it's integrated with your system services directly. I told him, that maybe rare, but I'm actually happy to not use Google apps as much as possible and especially not within my operating system. Another point he made was that 5G'A is blocked by Google, about that I know nothing to be honest.

Some Android forks are indeed quite nice, but the issue has always been the updating model, upstream maintenance and compatibility. With Harmony OS a large cooperation with the consumers in focus and the one developing the entire hardware stack is behind the OS development and maintenance making it safer against supply-chain hacks and a deeper integration possible than any other OS.

The next version of it, HarmonyOS NEXT is microkernel based, and they have two new languages of their own.

ArkTS, inspired in Typescript and similar nodejs runtime.

Naturally due to performance problems, they decided to come up with another one, also Typescript inspired, but ahead of time compiled, GC and effects.

It is called Canjgie.

This naturally is a big effort rebooting the whole ecosystem, it only works because Huawei could focus on the Chinese market after losing Android.