Many pool services, including the ones in my area, just use Trichlor pucks and deal with the extra cost of having to balance pH and prevent algae growth through the use of additional chemicals such as PolyQuat 60 algaecide or phosphate removers at extra cost. I asked one of them why they didn't use an automatic dosing system such as The Liquidator or a peristaltic pump and they said that many of their customers have kids and don't want concentrated chlorine chemicals on their property, period.
As I believe was mentioned on another thread, there are some pool services that have the CYA level very high at around 100 ppm and dose using unstabilized chlorine (usually chlorinating liquid or chlorine gas) to around 14 ppm FC which then drops over a week to around 4 ppm FC at which point it's dosed up again.
BBB is not the only method; it's just the lowest cost and least hassle, especially if there is some form of automated dosing (or on-site generation as with an SWG). Also, if one has 50 ppm Borates in the pool, this not only acts as an additional pH buffer, but has some algaestatic properties. It may not completely prevent algae if the chlorine gets close to zero for too long, but it will help slow it down if it just gets low for a short time.
Richard