They are good for pollinators

WEEDS have invariably been considered unwanted by modern agriculturists who have always laid emphasis on their removal. They affect crops by competing for nutrients. India loses an estimated 30 per cent of its crop yield every year due to weeds. This is more than the damage wreaked by pathogens like fungi, bacteria and viruses (16 per cent) or by insects (12 per cent). Yet farmers who spend money on herbicides would be surprised to know that weeding adversely impacts the entire food web.
Researchers in Finland found weeds important for sustaining birds and bees