The size of the retirement protest was larger because it had more time. This is more like an explosive spontaneous uprising of destruction targeting the rich that has spread from one city to many cities.

Honestly the numbers for both these, and the previous pension reform protests seem to be all over the map depending on the source. The consensus I'm seeing seems to be that these protests are far smaller than the pension reform protests earlier this year. More localized as well.

It’s less about the number and more about the violence, these protesters are taking part in looting, vandalism and destruction of public property.

Source: I live in Paris and I can see the destruction around me

Nah, the pension protest had much larger popular support, as it affected basically everyone. Most of the demonstrations here are just walks to protest about police brutality and the pointless death of a kid. And then you have the actual riots that make a lot of noise but don't have actual support.