If I recall correctly the maximum Noise Reduction Rating (NRR) for earplugs and earmuffs is around 30db. You can combine the two for a slight increase in hearing protection but you still hit a limit because of bone vibration.
Is there PPE out there to go even further beyond this? Where would it be commonly used?
I did not. Read it. It is a quote from the article after I verified the reference. It is a toxic bias of group think fools that take no time to read past what they want to see.