there is no doubt the deadlift is the primary low back exercise along with dips and chins it’ll go a long way to improve the integrity of the muscles that track up and down the back.
one huge mistake lifters and power lifters make is NOT including the most productive part of the exercise- the “negative portion” they just drop it ffs.
side bends (and I mentioned often) are an excellent exercise to bridge the gap for a strong back.
but I always stress strongly that to do all this one must be patient and to make sure that if one wants to get in shape- you first need to be in shape.
that quote will mean nothing to a young beginner and in a lot of cases a seasoned lifter too, some folks are lucky and some aren’t.