Sure, and man are the easy wins satisfying. Fixing shitty data access methods/patterns is one of the easiest ways to get a "WOW!" out of a client or product owner if you're stuck in the low-visibility silo of backend dev[0]. I've just been repeatedly surprised over the years at how very, very many people are making real money, and consistently finding work, yet don't seem to know which way is up. And I don't mean greenhorns, though often they're given comical levels of responsibility (typically by the cash-strapped or cheapskates) resulting in some real messes, which has a similar effect to when an incompetent "lead architect" or an experienced team nonetheless without a clue between them is set loose, which is just as common.

I harbor no ill will toward these folks. Hell, selfishly, I'm glad there are so many. Having half an idea what you're doing is guilt-inducingly easy, pays amazingly well—especially after the confidence-boost and resulting swagger and negotiating attitude that comes with seeing this kind of thing over, and over, and over, for years on end—and it's disturbingly easy to be a or the "smart one" in the room when you're kind of a dummy, in fact.

[0] Dear backend devs: if you don't simply love backend work and/or if you aren't very well appreciated compensation-wise, and especially if you have long-term career aspirations that involve shifting more toward the biz/architect/management side for the extra social status and higher late-career pay (in most of the industry outside the huge West-coast tech companies, anyway), consider moving to more high-visibility pastures—though ideally not web frontend, as, incredibly, it's still a trash fire and comp is so-so, mostly. Unless you just like trash fires, which some people do.