

we’d first have to define the difference between nat. and eth., they seem to be ~the same thing to me
Nationality is the nation you are a citizen of. Ethnicity is the ethnic group(s) you identify with.
In Europe, these are largely the same. The only multi-ethnic countries I can think of are Russia, the UK and Spain.
But in most parts of the world, one country would have multiple ethnic groups, and one ethnic group may be spread across multiple countries. For example, China has Han people, Mongols, Muslims, Tibetans and so on. Of these, the Mongols also live in Mongolia and Russia, the Tibetans also in India and Nepal, and so on.
Again, in Europe it seems to be common for people to identify primarily with their nation (except Catalans, Scots, etc.) But elsewhere, since the borders were often drawn by outsiders, people often identify more with their ethnic group. This unfortunately leads to a lot of conflict.
Huawei is being forced to do it. But like Android, their HarmonyOS is not 100% open-source. There’s also KaiOS, which some Nokia and Alcatel, and all Jio, devices use.
Both the ones I mentioned are designed to be more memory efficient. KaiOS in particular is aimed primarily at feature phones and entry-level smartphones.