With their headquarters largely empty amid the pandemic, tech companies are reconfiguring their open-plan spaces to appeal to employees when they return, with opportunities for collaboration and focus workers can’t get at home.

When historians of the early 21st century look back on the pre-Covid era, one of the absurdities they might highlight is the vogue for gigantic, open-plan offices. The apotheosis of this trend of breaking down barriers between co-workers must surely be Facebook Inc.s 433,555-square-foot Frank Gehry-designed open-plan office at its headquarters in Menlo Park, Calif. Opened in 2015, its now a ghost town, a monument to offices vacated by the pandemic.
Cramming cavernous spaces with as many desks as they could hold might have…