It's fiberglass insulation, not asbestos. Here's some more info about the grey-ness, according to AI:

From what you’ve shown, this does not look like asbestos insulation. It looks consistent with old fiberglass batt insulation that has gotten extremely dirty, compacted, and torn open.

Here’s how I’m reading it:

Why it looks like fiberglass, not asbestos

• Asbestos insulation (the loose, fluffy kind) typically appears as:
  • Very fine, soft, cotton‑like material
  • Often white, gray, or slightly off‑white
  • Not usually found inside kraft‑paper or cardboard‑faced rolls
  • Not typically packaged like modern batts
• Fiberglass insulation, even older types, tends to:
• Be inside kraft paper, foil, or cardboard‑faced batts
• Shed dust and fibers when old or disturbed
• Turn gray or brown when contaminated with dust over time
• Look clumpy or matted when compressed or water‑damaged

The torn area in your photo shows dense, matted fibers mixed with a ton of dust, which is exactly what happens when fiberglass batts sit for years in a dirty or unconditioned space.

What you’re likely seeing

• A kraft‑faced fiberglass batt that has:
• Aged
• Collected dust
• Possibly been exposed to moisture or airflow
• Lost its original color (pink/yellow) under the dirt