It varies. The mesh makers leave it to the surgeons to decide. Some tout that their product does not need fixation, some say that it is optional. Some, like Progrip, are designed to negate the “need” for fixation. My surgeon was proud of his method of creating a space that he thought contained the mesh so that it did not need fixation, even though it was Bard SoftMesh.
Unfortunately, you will find many surgeons who are still focused on fixation (fixated on fixation) as the cause of mesh pain. The reality is that mesh pain occurs with and without fixation.
Fixation is another distraction away from the root cause of chronic pain. Beware the marketing material that promotes fixation-free mesh materials. There are many people with Progrip who have chronic pain, and no fixation.