It all depends on the vlogger and their personal preferences. Some vloggers prefer to prepare their content ahead of time, thus choosing a vlogger script, while others prefer to work more impromptu.
A video script can be useful for vloggers who wish to cover specific themes or include specific components in their videos, or who want to organize their content in a specific way. Vlogging without a script, on the other hand, can be more spontaneous and allow for more genuine, unscripted moments, which can make the material feel more authentic and accessible to the viewer.