Brushless drills are more common now, whereas before brushed drills were the norm. Brushless drills offer better performance and durability when compared to brushed drills.
A brushed drill delivers maximum power all the time, whereas a brushless drill only provides enough power to do the job.
Brushless drills are more expensive than brushed ones. The higher cost of a brushless drill is worth it in the long term due to the benefits which cancel out the higher price.
Brushed drills heat up after a while, which causes the brushes to wear out and be replaced. Brushless drills, on the other hand, create no friction and run cooler than brushed drills.
Manufacturers have mostly switched to brushless motors. However, cheaper options seem to use the brushed motor still.