Pre-tubeless I actually managed to pinchflat 3 times in a single descent of Garburn.
Since going tubeless I haven’t suffered anything like the same failure rate but no they are not infalable, just a lot, lot better IMHO.
On the rare occasions that I’ve split a tyre beyong the healing capabilities of Stans fluid and had to put a tube in, I have always, without exception, managed to pinchflat the tubed tyre again within the next mile or so.
For me, this is sufficient proof that the bit of faf is worth it.
Dual ply High Roller on the back & Single ply ST Minion on the front, Flows, Stans, sorted.