The problem with defining "indigenous lands"

The American left, in their endless quest to undermine and destroy western civilization, especially in the United States, among the literally thousands and thousands of tactics they have come up to try to do this, have strongly pushed the idea of respecting the rights of American indigenous people to their ancestral lands and, at the most radical, returning it to them.

This entire idea has many, many problems with it.

One of the major problems is defining, exactly, which part of the land belonged to which tribe and why, or whether it belonged to any tribe at all.

When European settlers inhabited the North American continent (sometimes warring with and replacing the indigenous people, sometimes just settling on a completely uninhabited part of the continent) there were somewhere around 5-10 million people in the entirety of North America, by rough estimates. That's about the population of Switzerland.

The continent was extremely sparsely populated and there were vast expanses of wilderness that were not only completely uninhabited but where no human had ever even set foot anywhere near. There were literally average-European-country-sized such areas that had zero population, and had never had any kind of population ever.

So the question becomes: Who exactly "owned" those vast uninhabited areas before the Europeans? And based on what, exactly?

Sure, if you were to ask some tribe members "did your tribe own this Switzerland-sized area of uninhabited land before the Europeans came and settled there?" most of them would say "yes", obviously. But what is this based on? Those tribes never inhabited those areas, never set foot on them, never visited them, never hunted there or anything. Should we just take the word of their distant descendants at face value on a "trust me bro" basis?

And even the small areas where their ancestors did live... How exactly do you determine the extents and limits of those areas?

There were no maps, no surveys, no agreed-on borders of any kind. Heck, the natives in the North American continent didn't even have any kind of written language system at all (yes, look it up.) There's absolutely no possible way of corroborating the extents of their "territory" that they supposedly "owned".

In the modern world each sovereign country has an extremely well-defined territory, with extremely well-defined borders, to the centimeter. Not so back then. Not even in Europe, much less in the American continent. Even in Europe it was more like a set of kingdoms with very fuzzy ill-defined lines, controlled on a "who has the military force to claim the resources of a particular area" basis. Historians will draw maps delineating these areas, but they are just extremely rough approximations based on some concept of "control" by a particular kingdom. There were some maps even back then, defining some concept of "our land area", but these, too, were more defined on a "trust me bro" level than actual international agreements. Heck, the entire Westphalian sovereignty system (that defined the concept of independent autonomous sovereign countries with well-defined borders and well-established political autonomy) wasn't established until the late 1600's, centuries after the conquest of the Americas.

And on top of that we also have to question the entire thing on a more "meta" level: What claim did these people have to these lands, other than just living there? On what basis?

Most if not all American indigenous tribes were constantly in war with each other, fighting for territory and hunting grounds. Whoever happened to have the more powerful fighters in a particular area essentially claimed control of that area. Extremely fuzzily-defined area with no clearly established borders. Who exactly should we assign (and perhaps return) these lands to? The tribe that lived there last, before the Europeans? The tribe that they took those lands from? Or the tribe even before that? How far back can we trace "ownership" of a particular area?

And that's just the areas where they lived and hunted. That's not even going once again to the question of what claim they could possibly have on the vast expanses of completely uninhabited wild land.

There's absolutely no way to know, or even define, what areas exactly were "owned" by whichever tribe, or if it was "owned" by any tribe at all. Trying to do that is absolutely futile. Declaring a particular area, with any sort of clear borders, their "ancestral lands" is completely arbitrary.