I’m not really sure I agree with you, @John_E. I try to take something from each of the covers I do. The last one is a lesson in simplicity - basically two notes, yet the rhythm drives the song along. It is the hook and heartbeat - I heard the song on iTunes and thought, “Wow, that’s good!” Yes, it’s pretty easy to master, but that doesn’t take away that core element; a hook doesn’t need to be complicated to really work.
Equally, I’m currently working on one that is a variation of a 12-bar, but a specific phrasing that I haven’t played before, and it’s not actually a 12-bar. While the progression is 1-4-5, it sits on the 1 for 12 / 16 bars, then moves. It messes with your head - you want to move, but can’t. It’s really interesting. So again, seemingly simple, but not so easy.
Of course, I should also put some more complex stuff in there too. I’ve just recorded a McCarthy (Beatles) cover and I have a few more I’m learning for the band. Will I keep the 2 a week up for the next 12 months? Not sure, maybe, probably…one of the fantastic things about doing it is that it means I listen to an incredible range of songs; I hope in my sharing, some others might get turned on to the amazing variety of material that out there, old and new.