When that happens, it seems to be because the location (bottom of cliff) has extensive bush covering around it.
That being said, I know nothing at all about any of the above cases. There may have been bad weather involved too, which would probably also be a problem for a jet pack solution.
Try to imagine a world where helicopters work in some rescue situations, but not so well in others.
Tight areas... maybe. But if the tree canopy is too tight, I don't see how a dude with a jetpack is truly going to navigate that efficiently. They'll just find a near by clearing to land and hoof over... which, the same can be said of someone in a copter. Though, the one from the copter can ruck 70+ pounds of life saving medical equipment because they're not carrying jetpack equipment.
Forest Fires? I mean, what advantage do they have to smokejumpers? All that extra jetpack gear means less firefighting gear on them.
Look, it's cool. It's awesome. I also want to be the first person to get a DUI in a jetpack. But for the price of a cheap helicopter and going to a scenario such as a fell (https://en.wikipedia.org/wiki/Fell)... a less complex helicopter that can ACTUALLY carry gear seems like the smarter investment for a search/rescue department.
If cost that much of an issue, a paraglider costs 1/10th as much and are likely much safer to operate. Or if getting a single person on site is all you need, tiny helicopters cost as low as 50k new.