I would've loved 'Someday's Dreamers' if it had actual depth to it. The basic premise is that magic can be used to make people happy. In line with this, our overpowered protagonist, Yume, dreams (heh) of making everyone in the world happy using her magic. The manga then proceeds to provide situations in which Yume uses magic of all kinds, with seemingly no restraint or constraint, to make people happy...at least on the surface. The main issue with the way Yume is written, is that she sees no major personal consequences for her mistakes. Her impulsiveness and the resulting mistakes are, thus, treated as fine because "shemeant well"...even when someone literally ends up being stabbed for it. Yume doesn't really grow as a character, Oyamada (her instructor) gets over his trauma pretty quickly once Yume intervenes, and the other characters might as well be cardboard cutouts.

You shouldn't go into this manga expecting a detailed explanation of how magic works, who can use it, what limitations there are etc. At most, there's a brief mention of it being illegal to create money out of thin air, but Yume does it twice and is (predictably) never punished for it. It also takes her a surprising amount of time to figure out that magic can't be used to cure everything, despite it being stated outright in the first pages of the first chapter and, presumably, being among the first things taught to an apprentice mage.

One thing I was pleasantly surprised by was that the subplot of the old lady, which started in volume 1, influenced the rest of the story. Even so, I found myself rolling my eyes at the writer's inability (or lack of interest) to devote the rest of the story to Yume processing her obvious PTSD, instead of having her fix someone else's problem in order to fix herself.

In the end, it's a story that exists. Neither particularly impactful nor groundbreaking, but will suffice if you have nothing better to read on hand - but I bet there are other manga out there who did things better. If you don't feel like sitting through the entire thing, read the first and last chapters only and you'll get an acceptable story. At least the art is decent.