I'm convinced that distributed teams, where team members need to cooperate a lot, will be almost always (often significantly) less productive than co-located teams.
I'll mention something trivial yet having strong effects. While working, I often come up with a bunch of random work questions. When co-located, I often look at the person who could answer / I could discuss with. Are they in the office currently? Are they currently looking deeply focused or are they already distracted / looking bored so asking them would not probably cause an issue? If yes, I can ask them and get an immediate answer to solve a problem / clarify my thinking etc.
There's no corresponding possibility with WFH which leads me to shooting an IM which is often answered too late thus delaying the problem-solving. You could say that the difference between getting an answer in 1 minute or 10 minutes does not make much difference, but in reality it can have big consequences. With 10 minutes latency, you've probably already switched contexts and will take a look at the answer later, thus introducing even more delay.
Another thing I noticed that different people manage differently with WFH. Some people communicate often and even build relationships over Zoom calls with ease. Such people typically have great communication / interpersonal skills in the first place. But OTOH there are people who hardly ever initiate communication, very often keep muted in most calls etc. Those are usually the more quiet ones in IRL, but in WFH they are even quieter, and it shows. This is very much amplified when the team did not ever meet each other IRL.
I think that the "best WFH performers" can form great distributed teams. But it's not going to work for the majority of teams, who are likely to see productivity decrease.
I actually believe most of the WFH communication problems could be solved / mitigated with better technology (VR office), but we're simply _nowhere near_ that.