As a counterpoint to the "deadlifts fix everything" folks, I regularly (4-6 hours weekly) do deadlifts, squats, overhead squats, air squats, goblet squats, pistols, weighted pistols, muscle ups, snatches, situps, pushups, handstand holds, handstand pushups, power snatches, toes to bar, toes to elbow, thrusters, pull-ups, planks, couch stretch, pigeon stretch, vinyasa yoga, kettlebells etc etc etc. Pretty much total insanity.

I've been a desk jockey for nearly a quarter century, and have had constant low back pain for nearly as long. My back feels terrible every day, particularly when deadlifting, or standing up from sitting on the throne for a bit. Chiros haven't helped (100% quackery imho, I've tried a dozen, and really want it to work), X-rays show nothing wrong.

The only thing that has helped has been classic "80's ladies" leg movements (bird dogs, fire hydrants, movements like shown in the linked video), along with foam rolling out tightness in the hips.

I suspect my hip flexors are extremely strong in one direction, and extremely weak in the opposing direction (medial glute), pulling my pelvis out of whack, and thereby hosing up my lower spine.

Anyway, sometimes barbell work doesn't help. YMMV.