Oh, c'mon! They tell you to never change ATF and to use the thinnest oil and longest OCI that would make it till end of car's warranty. They want total ownership cost look low while pleasing the g-man and earning credits.
If one wants the cheapest while compliant with specs - just follow the specs. There is nothing wrong with DOT 3, just flush it every 2-3 years depending on driving and weather conditions.
A few of us on the forum use Bosch ESI6 fluid, I use and like it too. ESI stands for, as per Bosch: Extended Service Interval (ESI): Lasts 100% longer than DOT 3, 50% longer than DOT 4, and 10% longer than DOT 5.1. Either way, I change mine every 3 years. It may not be the cheapest but it worked great for me so far, no corrosion or deteriorated/bulging rubber brake lines after 10+ years of service, no floaters in the drained fluid either.
LV (low viscosity) fluids work better with ABS systems and in winter conditions, and most cars have ABS now, and you do sure want ABS to work when braking hard on snow or ice. I have video footage from my dashcam of cops effing up and falling over when exiting their cruisers while attending a multi vehicle pile up at an intersection, one of my co-workers was involved in the crash and is on video, black ice as we call it, the one you don't see. Tires and brakes are more important than how strong the engine is.