Nature loves untidiness, biodiverse places are messy but in a good way, there is decay, disorder and disturbance. The best strategy to protect wildlife is to leave it alone as much as possible.
Long grass hides litter, cushions the ground, gives a home for insects and small animals, soaks up noise, catches dust, cleans the air of dust and pollution, calms the weather and invigorates the soil. Different species of plants come and go through the year in a constantly changing scene of opportunities for nature to thrive!
We need a world peppered with 'scruffy spots' for birds, animals, bees, wasps, beetles, ants, butterflies and worms because there is no life on earth without an ecosystem to support it.