How are you doing your rows? For most people, the back is in a much less compromised position while rowing, and it's also largely static. Deadlifts are dangerous when people hunch their backs while lifting very heavy weights, which can happen at almost any point in the movement. For some people (especially those with short arms) a hunched back can be practically unavoidable.
Deadlifts really aren't worth the injury risk.
Also, I don't think that there's a very good correlation between deadlift capability and muscularity just in general. They really don't do a lot to activate the lats/traps. Rowing is more obviously useful for bodybuilding.
I do mostly chest supported rows due to the idea the more stability you have the more you can engage the target muscle. If I'd do barbell rows, if I did a Yates row I I'd keep the bar brushing against the knees and would row below the belly button, because as the bar drifts away from the body the low back has to stabilize more. If I do a Pendlay row I'd also row low on the stomach but these can also be done higher up if you want to target the upper/mid back.
The rounding of the back can be bad if that's not a natural posture for you - it's individual. The back can also adapt to all manner of awkward movements. In physical therapy there is a debate whether the Jefferson curl is dangerous or if it's good to strengthen all possible ranges. I'll post a video of Konstantin Konstantinov and his rounded upper back and also my deadlift video as I have a rounded back as well. I started getting upper back pain a few years ago and I was sure I had herniations. I was surprised when an MRI showed no herniations despite deadlifting 660lbs+ pretty much every week for over 20 years straight. Check out the Jefferson curl. You don't have to deadlift extremely heavy - I think it's beneficial for back health as a strong back doesn't get injured as easily. Let me know what you think

For us this is a natural posture. I have some kyphosis. The body adapts.

Lower back is straight
Jefferson curl
My lower back is straight but upper back is in it's "natural" somewhat rounded position
It's true that deadlift strength doesn't correlate to muscle size a lot of times; I'm an example of that. But it might be true of other exercises too. If you have good bodybuilding genetics I think deads will build muscle for sure. I think deads have contributed to Jordan Peters' muscularity. What do you think? I think a lot of people just hate doing them. I have the opposite bias
