Why are brake ferrules longer than shift ferrules?
Stepped brake ferrules, the long type you mention, exist for using 5mm compressionless (aka braided) brake housing on levers and brakes that have a plain 5mm bore, intended to take conventional spiral brake housing without a ferrule, such as many brifters and road calipers. You must use some kind of thick-ended ferrule with compressionless brake housing, or else the wires will pull through, same as using compressionless shift housing without a ferrule. Using them elsewhere, such as housing stops, is basically incorrect.

If you want more premium 5mm ferrules than the commonly encountered plated ones, a couple companies make them, Wheels Mfg and Jagwire for example.