Open Office was a cesspool of disease, even before covid it was problematic:

https://www.passporthealthusa.com/employer-solutions/blog/2020-2-how-do-open-offices-affect-employee-health/

Studies have found that that those who work in open offices are more likely to take short term sick leave or a sick day. Those employees might be using 62% more of their sick days due to the environment. Employees with this office layout are also more prone to headaches and respiratory problems due to weakened immune systems.