I am the only one who does not trust media that can be deleted?
Pendrive, hard disc, SD card and all rewritable media may have accidentally deleted your files, or caused by computer viruses.
Call me old, but I trust more in DVD-R medias high quality.
Not only are you old, but you are misguided.
First, the question is about delivery, not archival storage. If a thumb drive goes missing or gets erased just do another one, but it has never happened to me.
Second, I had so many CD's and DVD's write badly, get scratched, get broken etc etc I can't understand anybody but a china plate merchant finding them any good for anything, that is why I have not used them for years.
Third, time has passed you by, you can protect images from erasure on a thumb drive, just lock them, then it takes a concerted effort to "accidentally" delete them. Indeed it you limit permissions on the drive it can't get a virus either as nothing can be written to it.
Burning discs is slow, unreliable, and expensive when compared to reusable thumb drives or free online folder delivery.