The entire South American primate and caviomorph rodent lineages (everything from capuchins to capybaras) descend from African ancestors that rafted across the Atlantic on vegetation mats roughly 40 million years ago.
When the Isthmus of Panama closed (~3 million years ago), North American placental mammals poured south and drove a large fraction of South America's endemic fauna—native ungulates, many marsupial lineages—to extinction.
Yeah. Some species get crowded out, maybe we should avoid that in a lot of cases, but is not the capital sin western people have been brainwashed to believe it when they replaced their christianism with new age Gaia worship. Species get extinct, eco-systems change, sometimes it is worth preventing that, in other, who fucking cares?
The big deal is that when a species becomes invasive, the effects can cascade. You don't just lose their direct competitors and their prey, you can lose anything they pollinate, nest in, are nested in, etc. You can replace a diverse ecosystem with a near-monoculture.
Of course, if you don't hold the fundamental belief that biodiversity is Good, and is Better than raw biomass increase, I see why this doesn't bother you, but I do hold that position.