Having done some volunteer work with a Master Naturalists of Texas chapter removing the most invasive species from the parks and natural area parks in the past, it really makes you realize how much harm is done by the invasive nonnative plants. To restore some native species that have gone away because of previous development or being crowded out by invasive nonnatives plants, it's very hard. They sometimes have to be cut down or (unfortunately) chemically treated repeatedly over years. Some nonnatives also don't support the native insects or wildlife, essential parts of the ecological web of life for our natural world. Have you ever read Douglas W. Tallamy's book Bringing Nature Home? I'm not an dogged advocate of regional native plants only, but it's really getting out of control! We must all do our part to preserve as much of the flora & fauna that evolved to work together in our local areas long ago. I really wish time travel were possible. I know Texas was much much different many hundreds of years ago. I bet it was absolutely amazing!
