I agree in principle dude, I dont stress my plants more than the biology I use does for me. I dont top bend, pinch or cut unless I absolutely need too.
Technically, the only reason a plant would grow a bigger root system, is to locate newer sources of food, air and water. If we provide everything our plants need, then the roots will spend less time hunting new sources and the system will cleave itself and regrow within a confined space, well demonstrated by solo cup growers.
The concept of root bound plants is little discussed in a true sense, its all anecdotal BS with very little actual science to learn what actually happens to a plant in a root bound condition. What we can say is that our plants often respond with traits that benefit humans when we apply moderate stress, as in the case of AAC1 production or ADH1 via yeasts. These biological modulations can insert gene code in to plant sequences from which we can benefit by raising the plants internal defense systems, thereby increasing oil production and trichome density, improving both the quality and shelf life of harvests.
Everything is about the use of energy, a plant will subvert energy to reduce stress, this will impact other systems related or not directly. What does your book say? Does it say root bound is bad because xyz systems are impacted? Or does it just say its bad in a general and no science way?
Most books are trash, knowledge moves faster than print. may be someone should do a proper study on how root bound plants are really impacted, perhaps we might learn something and stop guessing or personifying our crops and style with our own unfounded concerns