Brake fluid change?

I don't know how many on here remember honing the wheel cylinders for drum brakes back in the 60's with a honing tool inserted into an electric drill. When you removed the rubber ends and run your fingernail inside the cylinder you could feel where the ID of the steel had been etched away from the moisture. The depth of etched valleys were deep enough to cause the rubber seal to leak brake fluid all over the brakes, which to me is serious for a 20-30k lb MH coming down a steep hill. I don't change mine every 2 years, I have a Chevy chassis but have changed it probably 3-4 times over the last 15 years. What I do is jack up the front end and gravity drain the fluid starting in the rear the working my way to the front. I suck out the old fluid from the MC first with a turkey baster and add new fluid so only the lines have old fluid. When the fluid comes out clean I close the bleeder and open the next one. I can do this job myself and it does not take as long as it sounds.