Or, then, you just don't trust your employees and want to watch over them all the time.
Neither of these reasons touch the actual reason why you are in the office - to create added value. Hence open plan office is an environment that the market has selected for all the other reasons, except to be a good place to work.
Some people like open offices, other don't.
The overall picture from literature and practice is that if the cadence of the work is "like in NASA flight control" then the easy communication aspect is an actual asset.
On the other hand, if you are mostly coding and doing other sort of deep work, then an open plan office is openly hostile to productivity.
For example, if noise level increases 10 dB it decreases productivity by 5% [0].
Personally, having worked in all sort of configs for two decades, my capability to concentrate, productivity, and happiness in an open plan settings plummets.
[0] Dean: Noise, Cognitive Function, and Worker Productivity "https://joshuatdean.com/wp-content/uploads/2020/02/NoiseCogn...