A massive amount of these extinctions is simply the wholesale import of pests and rival plants across the world.
Think brown snakes in the tropics, zebra mussels in the Great Lakes, snakes in Florida, transplanted crops plus their diseases and pests around the world.
The end result will be a loss of genetic diversity as many niche species are replaced by hardier international varieties. But the result will also be a more stable ecosystem as niche species that can’t adapt are replaced by those that can, except for those areas where people don’t live, farm or modify.
That did not work so well for the Irish, a couple of hundred years ago.