It's about investment funds and shareholders owning commercial property who push for RTO out of fear of their portfolio going down in value if people are not using the offices.
To be fair I think the only reason the conspiracy even exists is because, apparently, nobody knows what RTO is really about. IMO it's mostly just a power play and insecure executives, but they won't come out and say that of course. We're left to speculate, and naturally conspiracies thrive.