There are such things as anti-avalanche devices used all over Europe to stabilize slopes above towns, preventing avalanches from starting. Avalanche control - Wikipedia
Neither of these are appropriate for Everest, which is fine because they wouldn’t work there.
A biological agent that would operate at low temps and on freeze dried tissue, leaving the synthetic and metallic bits to blow away seems neat and clean. Problem is that such an agent would likely also happily attack living tissue.
Plenty of work being done on robot horses, but they’re not quite ready for active duty yet. Besides, there’s plenty of terrain on Everest that’s not suitable for a quadruped, whether mammalian or robotic. A robo-horse would also need a whole lot of energy to make the ascent and descent, so someone is going to be lugging up batteries or fuel for it.
And then, once more, there’s that pesky question of who pays for all of this.
All this talk of helium, robot horses, and zombie viruses is ridiculous. Not feasible at that altitude and who would pay for it?
Here’s a much better idea: each climber carries up a 3-foot section of metal playground slide. Train some Sherpas to weld them together. By the end of a few seasons, you’ll have a giant slide from the summit right down to base camp. Just drop the corpse on the slide and let 'er rip. Wheee!
I find this idea totally unrealistic. Sherpas don´t know how to weld and even if some of them would learn rudimentary skills, thick gloves they are using would make precise welding impossible.
If something like this is considered, it should be a chain of well placed trampolines instead.
The most realistic option by far is that every climber picks up a rock and places it on the body until they have a cairn covering the body and this is in fact what is actually being done.
Most of the climbers families are happy for them to remain on the mountain. Cover them with rocks to make a cairn, problem solved.
Burial up there typically means dropping the body down a crevasse, or sometimes covering the body with nearby loose rock which is only available in a few places where there are bodies.
Hey if you can handle the death zone enough to get to the top, you could instead not get to the top and bring the bodies a few feet down. While many people are willing to sacrifice a lot to get to the top, the same is not the case to drag the bodies a few feet down. SO we have lots get to the top, and bodies that do not move down.
Seriously? You think people are going to spend tens of thousands of dollars, and then not attempt their goal, in order to move bodies down a few feet? And as has been said, it’s pointless to move them down a few feet unless there’s some coordinated program to get them down.
And again, you haven’t really expressed why it’s so important to move them down. You don’t need to move them down to give them last rites.
You haven’t made a very compelling case for why they should. Suppose you went on vacation to Barbados and, on stepping off the plane, you were told that actually, there’s a pressing need for people to dig graves. You’ve got some free time, right? And digging graves is more important than lying on a beach sipping cocktails, right?