I feel like most Europeans would be considered “indigenous.” Unless they are immigrants living in Europe or their ancestors were immigrants, if they can trace their ancestry back to anywhere in Europe I don’t see how you could say they are not indigenous. The Sami are most-likely falsely considered the “only indigenous Europeans” because Europeans do not think of themselves as tribal people living off the land. This is obviously NOT what indigenous means. Most Germanic and Eastern European countries have been mixed with “non-indigenous” genetics like the mongols and turks, but probably, so have the Sami. The only people in Europe you could argue are the least “indigenous” by this logic would probably be southern Europeans who mixed greatly with north Africans, mongols ect. but it still seems odd saying Italians or Spaniards are not indigenous to the area as their ancestors have likely been there for as long as humans have been in Europe.