As I said, never trust those apps for that competitive number. They use a weird algorithm, that is not the holy grial (if it was the case, they could be plain selling those keywords for some thousand bucks).
Most people use this kind of metrics to filter from huge lists. For example, if you have a 100.000 list of something (keywords), maybe you may say: "I'm going to fillter all above 30 out of 100" and proceed from there. Then after that filtering you may get only 1.000 domains and keep on filtering with other parameters. Obviously when you do this, out of those 99.000 you filtered out maybe a 2 or 3% could have been great opportunities. But when you use this metric you believe that the opportunities it gives, on average are greater than the opportunities that it doesn't
Just a matter of statistics. From there, there is a point where you have to filter manually. The selected keyword can never, ever, be chosen by some automatic mechanism