The problem is that conflates very different actions.

Everything described in your quote is horrible of course and is a form of erasing an ethnic identity, but it’s still not the same as mass killings (including indirect forms like starvation or deaths in the Trail of Tears) to erase the physical existence of a people. Death is a significant step above assimilation and should be treated as such.

As far as settler colonialism being genocide, it still is under a definition requiring deaths. Millions of indigenous Americans were killed.