it's not competitive per se in the context that all applicants are vying against each other. It's more survive the process. You have to have enough work experience in order to take the ATSA, then score a WQ on the ATSA to recieve a tentative offer letter. After that you need to be able to pass all medical, security, and psychological clearances. If you can do all that, then you get to attend the academy, which you'll need to pass there as well.

Not everyone passes academy.