It has nothing to do with real estate. This is often echoed on social media but is baseless.

Companies typically chase quarterly growth over all else. Working from home benefits that while trying to fix real estate values is a long term thing, only offering a payout if they sell the building, which most companies aren't worried about. Companies tend to be very hesitant to hurt quarterly growth in favor of long term, iffy investments.

Even if they did care about real estate value, they'd rather all other companies return to office, boosting those values, while they could then remain remote and take advantage of both the higher real estate values and also the numerous advantages of remote work.

Boosting real estate values in this way is a collective action problem where most companies would need to work together for the greater good (as they see it). But if you hold this world view, that CEOs will screw over their employees for their bottom line, why wouldn't they also screw over other companies? They would. They would want other companies to work together to fix the real estate values while also benefitting from remote work. So it would all fall apart.

Here are more likely scenarios:

• SHAREHOLDERS. Shareholders don't like unused assets. "Use it or lose it". So, CEOs force return to office because they think it'll help the stock price. Shareholders are also likely to blame as evidenced by publicly traded companies being more likely to mandate a return to office.
• Personal preference. CEOs, and other executives who make this decision, simply prefer to work in the office and they prefer a full office to an empty one. Either cause: they have a very extroverted personality (likely how they got the job in the first place), they feel more powerful with all their underlings around, or they have a harder time working from home and can't fathom anyone being different.