I haven't tried such a prosthetic myself, but I've heard a bit about it. Yeah, reasonably you could wear it glued on for a somewhat long time at least, but eventually you do have to take it off to let the skin underneath breathe and wash it. I don't think it would be a good idea to keep it glued on for more than at most a few days but that's probably a very far stretch, as keeping anything glued onto skin for too long does damage the skin eventually. So no, it's not really more permanent than non-adhesive packers, but stays in place better and "blends in" more seamlessly with your own body better for the time you are wearing it.
I can only speak for myself and generalise from what I've heard around, but I and many other trans guys do feel that packers, no matter how realistic, can't quite replace being able to have one's own flesh and blood penis which bottom surgery does allow for. At least for me, having sensation in my penis is very important, which is something packers/prosthetics just can't provide me with.
So no, it could never replace bottom surgery for me cause it can't give me what I need to alleviate enough of my dysphoria to feel it's worth the effort or the price. But I'm sure that for others it could. Some can and do feel very connected to a prosthetic, but some of us don't/can't.
