Ditto to the above. Carbon brakes wear less at high temperatures, thus, for those aircraft so fitted, it saves money to use more brake and less reverse. Also, cold carbon brakes wear unevenly, reducing braking effectiveness for the day you'll really need it, the RTO from close to V1.
The original question asked the relative effectiveness between Brakes OR Reverse.
Reverse thrust is not considered for Rejected Takeoff or Landing performance on DRY runways. This is not because of any anti-Reverse Thrust stipulation in the certification rules, but rather that the same certification rules DO stipulate that one means of retardation must be held in reserve. The choice is up to the manufacturer, and 'by-laws' within the regulations do allow the use of all means of retardation, if a 15% penalty is taken upon the ASDA.
To date, I do not know of any manufacturer who has favoured Reverse Thrust over Brakes as the primary means of retardation, simply because the manufacturer wants the best possible results, and that is invariably achieved with brakes.
Most modern aircraft have 3 systems of retardation - Brakes, Spoilers, and Reverse Thrust. The manufacturers still put reverse thrust last, after spoilers, not because they apply significant retardation force on the ground, but because they spoil lift, put more weight on the wheels, and make braking more effective. For one of Seattle's products, with which I was very familiar in the numbers area, the contribution to the reduction in Accelerate-Stop Distance Required from Reverse Thrust amounted to 3 aeroplane lengths. The Brakes and Spoilers did the rest.
Wet / Icy / Slick runways are another story.
In practice, what is required is a sensible application of all 3 means of stopping, as alluded to in the many posts here.