I've never used a fire hose for silica control, but have utilized garden hoses and bug sprayers. My paperboy math indicates this leaves less water to process.
I'll have to request a chest x-ray on my next annual physical to check for scarring as I gave been in nuke D&D, deconstruction, demolition, and remediation since '76.
A garden hose or bug sprayer would not suppress fugitive dust on a 250,000 to million square foot building being demolished.

I don't see the fire hoses used much any more, the foggers (snow machines) have become more effective and for the reason that you mention.

Some times a fire hose was the only answer for the demolition of an elevated structure such as a contaminated chimney though drilling holes at the bottom and ventilating I think is better. We put a worker in a manbasket for elevated suppression but there are foggers on booms today.
For older large facilities the ground below is likely contaminated and will be excavated anyway so if there is no runoff it is not a big deal. The below ground excavation is phase two anyway when you move from RCRA to CERCLA regulations for below grade demolition.
Silica is frequently the secondary function of air quality control. Radiological asbestos etc. are usually the primary reason. Silica is in a wide variety of materials including the dust that is raised by trucks moving on the ground, if you are on a unpaved site you probably saw water trucks sprinkling the ground. That wasn't to keep dust off the office curtains.
Silica is 59 percent of the earths crust.