I think there's a bit of an issue of "efficiency" versus "efficacy" at play here. Yes, the Lessons are not, as a rule, efficient (that is, they are over costed for what you get). However, I'm a lot happier top decking a Professor of Symbology than a Thalia's Lieutenant in the late game because at that point I don't care as much about efficiency as I do about the ability to do anything at all.
No matter how high the power level of the cube, you still flood out sometimes, and Learn can help with that. Now, does that make it worth the space? Maybe, maybe not, but to say that including them doesn't make any sense ignores the fact that their upsides are entirely independent of their efficiency, so long as they're remotely playable. A backhoe is preferable to a shovel for digging quickly, but so long as you have a tool of some sort you're going to get the job done.
Edit: this is to say, yeah, individual learn/lesson cards are not great, but when you take the effects of a Learner and the Lesson together, you get a lot more done than most individual cards would.
Edit 2: I should REALLY learn to read things through for spelling when posting on mobile first thing in the morning.
No matter how high the power level of the cube, you still flood out sometimes, and Learn can help with that. Now, does that make it worth the space? Maybe, maybe not, but to say that including them doesn't make any sense ignores the fact that their upsides are entirely independent of their efficiency, so long as they're remotely playable. A backhoe is preferable to a shovel for digging quickly, but so long as you have a tool of some sort you're going to get the job done.
Edit: this is to say, yeah, individual learn/lesson cards are not great, but when you take the effects of a Learner and the Lesson together, you get a lot more done than most individual cards would.
Edit 2: I should REALLY learn to read things through for spelling when posting on mobile first thing in the morning.