This was exactly confirmed by an internal study at the company I work for. Engineers that depend on collaboration suffered a significant drop in output artifacts. Those being largely junior or mid-level engineers. Staff engineers actually did better, although ironically they tend to be the ones coming into the office consistently (anecdotally).
One of the most surprising takeaways was that while engineers in the office more often claimed they felt less productive in the office than at home, in-office engineers tended to have higher productivity and WFH engineers when the actual numbers were examined.
One of the most surprising takeaways was that while engineers in the office more often claimed they felt less productive in the office than at home, in-office engineers tended to have higher productivity and WFH engineers when the actual numbers were examined.