Though full suspension gravel bikes, heres one from google:
as im thinking about this more, i dont like them
but i do understand their purpose
something like this would be, with flat bars, ideal for my commute, because its railroad ballast, a regular rigid gravel bike would have a terrible time and a mountain bike is overkill for the greenway portion that comes after that
and then you kinda just have a weird geometry mountain bike thats a little better on flats? thats the issue, they blur the lines so far that i cant tell theres a line anymore, but i do see a use case where they are the ideal tool