Those are hard to compare, especially at Home Depot. They are always having combo deals. Those are also the cheaper lines, the MAX XR and M18 FUEL are where the prices separate. That’s the top of the line of each brand.

https://www.homedepot.com/p/DEWALT-20V-MAX-XR-Lithium-Ion-Cordless-Premium-Brushless-1-2-in-Hammer-Drill-and-20V-MAX-XR-Premium-Lithium-Ion-4-0Ah-Battery-DCD996BW204/309377508#overlay

https://www.homedepot.com/p/Milwaukee-M18-FUEL-18V-Lithium-Ion-Brushless-Cordless-1-2-in-Hammer-Drill-Driver-Tool-Only-2904-20/320326855