It only seems that way if you don't pay attention. For example: https://www.invasivespeciesinfo.gov/take-action , and there's lots of stuff at the state and local levels (if you don't believe me, call your friendly neighborhood extension agent)
Are they actually effective? The above is local to just one town, if the next town over doesn't do anything the weed spreads anyway. There are also areas where no one ever goes like parts of national forests. Have any of these efforts done more than delay an invasive? I'm thinking of kudzu and pine beetles. I wonder if pine beetles are creating more CO2 than cars by killing trees. The problems seem complex and not easily solved, so it would seem the appropriate response would be to train more people who can do studies and find answers. Instead it's left up to local communities to form groups and try brute force approaches.
An example of an effort that has made no progress for 7 years, is getting worse, people are spreading the invasive further, and the experts say there is now no getting rid of it:
