You can essentially divide IC employees into three categories. First, those who are about as productive from home as they are from the office, but are on average happier working remotely (no commute, etc). That's probably circa 80%. Second, those who are well-intentioned but fall behind over time, because they are less proactive about maintaining soft skills - communications, cross-functional relationship management, etc. That's the bulk of the rest. And third, there are people who actively exploit the situation in ways that the company is going to have an allergic reaction work (outsource their work to a dude in India, half-ass three jobs at competing companies, etc). That's typically Further complicating this picture is the fact that line managers are not perfect either; there is an "out of sight, out of mind" aspect to it, and if a WFH worker is underperforming, it will on average take longer to address the problem, which has some ripple effects.
And on some level, the exec perspective is that the intangible gains in the happiness of the 80% that was previously willing to work for you in the office is not worth the horrors on the bottom end. So there is something resembling a credible argument for RTO.
At the same time, there is a degree of lazy thinking / bad faith on the exec side because the problems can be solved in other ways. You can retrain managers, you can improve performance management, you can monitor for certain types of grift, and you can accept some degree of added risk. In fact, you probably should if it keeps your top performers happier. But the overwhelming preference is for the easy choice of RTO.