As I said, "in an ironic twist of linguistic history".

This is a story about a new helicopter, in India. But in the america's long ago "indian" was applied to indigenous groups by people looking for a route to India who didn't know where they were. And then, centuries later, the names for those groups were adopted as names for American helicopters. It is a long joke that I guess not everyone can appreciate.

Tl;Dr: it's tricky. and because it's not that simple.

I don't know your background and maybe you're from a first nation or tribe, but there isn't a common agreement between the populations of existing tribes and nations on what is offensive or incorrect. This isn't to say that any term is acceptable, but Indians, however incorrectly labeled by a colonizing group a few hundred years ago, is literally how some choose to identify themselves here in North America.

I say this as someone from India and event there, there isn't a common agreement or knowledge to arrive at an "inoffensive" term for folks who live here. Most just use the descriptor left by the British and say "Red Indians" with no malice implied.

this was interesting to watch - https://www.youtube.com/watch?v=kh88fVP2FWQ

Because it’s not offensive or incorrect. American Indians have adopted and use the term themselves. Most official American Indian organizations are named as such, and not as “Native American” or “First Nations”, though the latter is also catching on, especially in Canada.