Can some one explain, when I look at the specs on each the brushless have lower RPM and less torque than the brushed.
Because you're probably comparing the specs between a finely tuned quadrapole brushed motor made by a company with decades of experience in turning out the best in brushed motors, against their first attempt at a brushless product. Not that brushless technology is new, but it is, for the companies whose spec sheets you're likely reading. Now read the specs on a Festool drill. They'be been in the brushless game for a long time.
In Milwaukee's first attempt, they went for a negligible drop in RPM and torque, BUT with that, you get over 50% more runtime, and a much cooler running motor.
Brushless has the potential to smoke brushed in terms of technology, but that is no guarantee that a manufacturer hits a home run every time.
Here's an example of how game changing brushless can be to an industry. For years, it was assumed that you could only achieve a certain thrust to weight ratio in an electric plane. That ratio mandated planes that flew like, well, planes. Now introduce brushless, and you can get a thrust:weight ratio of greater than 1, and you've now got electric model planes that can stand on their tails, or fly straight up.
So the Milwaukee Fuel gen 1 didn't have more torque or speed than the brushed motor it replaced, but that brushed motor was the end of the line for brushed technology, and the new Fuel gen 2 specs are quite a bit higher.