I change my brake fluid every 2 or 3 years or so. I live in wisconsin which often has wet roads. brake caliper pistons will bring in a little moisture into the fluid when driving in the rain. I suppose I would go a longer interval if I lived in an arid region. My previous BMW and Mercedes recommend 2 year intervals. Over the life of a car brake lines will corrode from the inside. Also, corrosion can form around the caliper piston and cylinder. Similar to the engine coolant, proper brake fluid maintenance for the life of the car will be most important when the car is old.
If you neglect your brake fluid you risk having a brake line burst sometime over over 100K miles or 10 years. Changing the brake fluid is very easy and cheap, once you get the hang of it. Especially with the Brembo calipers.
Same with engine coolant. Corrosion inhibitors in modern coolants are good for about 5 years of so. Then you engine innards will start corroding. If you neglect your coolant your old car will be bothered with failed thermostats, water pumps and holes in your radiator. You will wish you kept up with the coolant replacements when the car was young. (Note: The Stinger 6cy is a slight pain to replace coolant.)