All the unpleasant deadlift experience of the subject has nothing to do with the deadlift itself, most likely because you did it wrong. It's like someone will say that squats are bad for the knees and bench press is bad for the shoulders, but it's not the action that's wrong, it's the performer.
In addition to the wrong movements, there is a high probability that there is a problem with the subject's body, because for a person who can squat 115 kg, a 45 kg barbell is really not heavy, it is really difficult to hurt you, even if your deadlift posture is terrible, you should not feel pain
It is recommended that the subject find a professional to screen to see if there are problems in the motor system, such as limited range of motion or some small muscles are too weak, etc.
Back to the original topic.
A properly executed deadlift is not dangerous, and the benefits far outweigh the risks, as a single deadlift stimulates the entire posterior chain muscles and grip strength, which greatly improves training efficiency and saves you training time.
In addition, the correct deadlift not only does not hurt the lower back, it also prevents lower back injuries because it stimulates the lower back well and makes it stronger, and the stronger the lower back, the more difficult it is to be injured.
In addition to having problems with the movements, the wrong training plan is also one of the culprits that led to the spread of deadlift waist rumors.
As one of the most common examples, the vast majority of novices are actually unable to coordinate the amount of squats and deadlifts.
This is because there is a large overlap between squats (especially low bar squats) and deadlifts in terms of the target muscles to be trained, and this overlap includes the lower back muscles.
If a person can't coordinate the amount of squat and deadlift training, such as practicing a lot of squats and doing a lot of deadlifts at the same time, then it can easily lead to excessive fatigue and insufficient recovery in the lower back. In this case, the probability of lower back injury is very high.
All in all, ask if it's right and then why. A deadlift that is executed correctly is not dangerous, and the benefits far outweigh the risks.