Best high-current 21700 (30T) has just 3100 mAh, but can handle 35A continuously.
Up in capacity (S35) has 3700 mAh, can handle 30 continuously.
Up in capacity (40T) has 3900 mAh, can handle “25+A” continuously.
Then (Vapcell purple) does 4750 mAh and 15A.
Then (48G) does 4800 mAh and 10A.
Best high-current 20700 (20700A) does 30A and 3100 mAh
Then (Keeppower) does 16A and 4000 mAh (overrated to 4250, that’s probably what you mention)
It seems clear that 21700 are better in performance/unit (haven’t calculated performance relative to size/weight, these are quite interesting too). Also, since both standards are created by Tesla and 21700 is their final choice, I totally expect 21700 to receive more R&D in the future.