It takes a pretty good hit to get an airbag to deploy in some cases. I’ve been in two accidents where my car looked like I was hit by a train and the bags didn’t deploy. The accidents were not high speed impacts though. Still gave me a good whack and did over $10k in damage in both cases. But the airbags would not have done any good had they deployed. Heck they might have hurt me worse than the seat belt did. The thing is that with modern cars even a moderate accident looks like a train wreck.