Why do plants grow better de-weeded then? You maintain a garden?
Discussion
Do they though? I think there are many variables in such an experiment beyond simply selecting some species over others. Are you mulching? Are you monocropping? Are you supplementing with compost? Are your preferred plants perennials or annuals? What is the long term health of your soil?
Weeds, in the invasive sense, are indicators of imbalance or compaction or some other issue.