Tubeless won't make you immune from punctures. It's a pretty good option, but a relative pain in the nethers to fit and seal them, and virtually impossible trailside.
I would say that, to date, it's made me immune from punctures, in the true sense of the word - ie thorns, nails etc.
The only time in four years that I've had a problem was when I actually cut the tyre in the tread area due to hitting square edged rocks at speed (and at low pressure), resulting in too big a cut for Stans to seal. If I'd remembered to top the sealant up, rather than letting it pretty much dry out, then it would most likely have sealed though, so it was mainly my fault.
Anyway, I just threw a tube in, which I would have had to do anyway, tubeless or not, and repaired the tyre when I got back home.
I used to use ghetto tyre liners in 20" tyres on my racing sled dog rig twenty years ago, but if I was doing the same now then I'd be running tubeless tyres, no doubt about it.
And disc brakes too.......