Removing trash is necessary, of course, but grooming a beach with industrial-level tools can remove the nutrients that support various lifeforms. The sterile beach becomes a haven for human sunbathers, but is a literal desert, as explained by a longread at Hakai Magazine:
Santa Monica State Beach, considered by some as the birthplace of beach volleyball, ranks among the busiest in California. As many as 50,000 people flock to this stretch of coastline on a typical summer day, and, at its widest, the beach could potentially accommodate more than 30 volleyball courts. Visiting a freshly raked urban beach like this, few people realize that it can amass over 10,000 kilograms of trash during a busy summer week. After the Memorial Day holiday in May 2015, cleaning crews gathered 39,862 kilograms...Wrack, related to wreck, archaic meaning "shipwreck", now used to refer to seaweek or pondweed.
Just as humans may develop allergies from growing up germ-free, beaches are suffering from being too clean. Swept flat each day, the beach can become a biological desert, devoid of the rare plant and animal species that make the coastlines so special. Over two tonnes of decaying kelp get deposited on a kilometer of beach each day, a valuable resource for wildlife that is robbed by city cleanup crews on a daily basis.
Jenifer Dugan, a biologist with the Marine Science Institute at the University of California, Santa Barbara, has found that beach hoppers, 14-legged “garbage” cleaners that thrive on wrack, have been disappearing from the coastline. “What habitat is disturbed as much as those beaches in Santa Monica?” she asks. “No agricultural practice disturbs the fields twice a day.”
On ungroomed beaches and other areas with little human impact, beach hoppers’ population can reach 100,000 individuals for every meter of beach. And on each meter of beach, they’ll devour 20 kilograms of wrack each month. “The kelp gets vaporized!” says Dugan, who has watched it happen. But when the beach hoppers, isopods, and other invertebrates that subsist on the wrack disappear, shorebirds also go hungry. That’s why barren beaches in California lose birds like killdeer and the endangered western snowy plover. Grooming can also destroy the eggs of the grunion, an unusual fish that lays its eggs in the sand at high tide.