In my observation the primary issue with most people doing anything requiring persistance over an extended period of time is sustaining motivation. This should be self-evident in the number of "this is my 'n' th attempt to learn guitar" user intros here and on pretty much every learning site.

"Learning songs" is the active learning key to maintaining interest and motivation echoed unanimously by instructors on every learning site and those who have been there and 'can do' whose channels I frequent. I agree 100%, so that learning songs is my personal primary daily learning activity. It is the perpetual enthusiasm driver for active learning of everything else including repetitious scale work & theory I consider supportively subservient to that primary objective.

But, there's always a but, even for the disciplined the surest way to kill motivation in my view, certainly in the first few difficult years of learning, is to pursue that methodology with songs holding absolutely zero appeal to you as an individual and in which you have absolutely no interest in learning and so won't apply yourself with the necessary passion required to overcome the challenges.

So play songs you love and really, really want to learn to play. Everything else will follow. But what to do when they're not here?

Confronted by the 'can't' obtain the necessary licencing objection, my resolution has been to seek out quality song tutes elsewhere if what you want to play can't be found here. They're out there, not only on You Tube which is notorious for its copyright blocking alogarithms even of interpretations, but also legit on alternative pro sites. Seek, and ye shall find. The Gods help those who help themselves.