It does not, because what falls under legitimate interest is also quite clearly described.
Is it necessary for performing the service to end user? Is it necessary to support technical or legal issues in providing the service? (Trading data with other entities, marketing, etc ARE NOT, logging, debugging, security/audit logs ARE).
Creating BS claims for "legitimate interest" like IAB does is just setting yourself for big fines for breaking the law.
If your claim was true, the solution would be easy: I simply find a need for all data that I collect.
Problem solved? For sure not, which obviously falsifies your "idea" that it is so easy.