At Google, they found that engineers L5 and above got more work done with RTO, and engineers at L4 and below got significantly less work done. WFH is great but it doesn't work for fresh engineers (who are often the most gung-ho about it as well).

Did you mean L5 and above got more work done with WFH? Since the next sentence implies that it was the fresh engineers who were most impacted by WFH.