Hint: the one that is better engineered for its actual end use has more exemplars in the field.
Second hint: engineering a useful product is, in the final analysis, more important than inventing any product that doesn't satisfy the needs of the consumer.
Engineering isn't always discovery or invention, although those can be important parts of the process. The ultimate tests of engineering are Does it work so well the user never thinks about it? and Can everyone who wants one afford one?
The AK design passes those tests with flying colors.
There are other aspects besides performance. The AK-47 was subsidized to the tune of 25 million of them given away.
The AK-47 failed when it first came out. The stamped metal technology was ‘not ready for prime time’ in Soviet Union. The Soviet Union selected the SKS as superior.
They went back to milled receivers, but that made it expensive. Eventually they got the stamped receivers right. Schmeisser had a lot to do with that.
M-1 carbines had over 6 million made during WWII. They are still in production today. Copies (Mini-14) in other calibers are also made, and are sold for a lot more than AK-47 clones. If it costs twice as much, then that is an argument that it may just be better, unless you think a volkswagen is superior to a porche.