I really hope you are wrong in this prediction.
> but I have seen very few people find that their teams are any less productive and plenty that have found them more productive
I've seen the same. You hear about isolated instances of teams being less productive but like you said, most folks I've talked to said their team has become more productive with remote work.
IMO remote work is here to stay and is the future and I think it all boils down to not having to be co-located with your co-workers. Once management and HR figure out that this lets them have a 10x larger talent pool, they will get onboard (if they haven't already)