It is very possible to injure yourself with calisthenics. Shoulder impingement or tendinitis from pullups with too much intensity/bad form for example. Weight is weight.

This is not good advice and please remove the “basically 0 risk of injury” wording. Mobility is a limiting factor and poor body positioning WILL result in injury. Barbells are safe, progressively overloadable, and learning to move them is a straight line is what most people need to do before a lot of calisthenics training. Most people can’t even do 1 pull up.

From my son's experience in calisthenics and looking around at the group he sometimes trains with, there are definitely a lot of overload/overuse injuries, at a range from just needing rest to bicep tears.

Lots of overuse injuries in calisthenics:

https://www.tandfonline.com/doi/full/10.2147/OAJSM.S394044

Poor form is possible with calisthenics and that leads to injuries or other problems.