Look at everything not controlled with manipulation already even in the relatively restriction friendly commercial advertising space. If we go down that rabbit hole we'll have to mandate package colors and store layouts. No more milk in the back of the grocery store or using attractive people to sell products.

Even putting aside practicality altogether many people would probably choose manipulation that left them feeling more fulfilled over unhappy bland truth that their job is tedious repeated trips and waiting that is wearing out their car since they know they need something to help make ends meet.

It is accepted that good management is to make your workers motivated - not even the most radical of labor would complain that their boss is making work too engaging. One could argue the status quo is messed up but it is accepted.

It might even have good outcomes and be ethically consistent to establish a strong precedent against manipulation but it would be completely outside the overton window and look like trying to swat flies with backhoes even if it was completely right.

note that historically we've allowed all kinds of manipulations (like basically lying in advertisements, caveat emptor), in an abundance of caution to avoid infringing our 1st amendment rights (in the US).