Very good question (I know I look like an asshole right now but, would you say that driving a car at 100 miles per hour on a residential street is safer than driving a motorcycle in the same conditions? I hope not. They’re completely the same. Both deathtraps for you and those around you.
The deadlift and the squat are the same way. If you’re performing either of them with bad form or with way more weight than your body can currently handle (or tons of weight in general) you will be in a very compromising position and will likely hurt yourself given enough time. Now, the way you can hurt yourself does depend on the movement. With the deadlift, you can literally tear tons of back muscles, your hamstrings (your quad in my case. Because I was squatting the weight up)
Here are 3 useful, visual guides for correctly doing both the squat and the deadlift:
Squat (low bar):
Deadlift:
Deadlift (sumo):