(Sorry, your short comment inspired me. Sorry this ended up being so long.)

I imagine it's a hard balance to strike. These artifacts and mummies ultimately need guarding. They've been protected from the centuries only by obscurity alone. All the ancient tomb traps failed long ago. You could put him back in his tomb, but now you have to guard the tomb. Otherwise someone will break in there and steal it. Some oligarch would absolutely pay a fortune for the bragging rights of having Ramses II's mummy on display in their villa. With the shear number of mummies and historical sites in Egypt, if you left things where they are, the Egyptian government would have to pay people to guard thousands of sites around the clock. And you then have to worry about the guards stationed at these isolated sites being bribed to look the other way as the thieves break in. (Or becoming thieves themselves.)

Amusingly, the Egyptians of today seem to be in the exact same situation as those of 4,000 years ago. Almost all ancient royal graves were looted in antiquity. The discovery of King Tut's tomb was such a hurricane specifically because it was the only royal tomb we've ever found that wasn't looted. The ancient thieves were after gold and jewels. But today, if they put it up for auction, I imagine the mummy of Ramses II would probably sell for more than its own weight in gold. The ancient thieves mostly tore apart mummies to find jewelry buried within the wrappings. Today the mummies themselves are the jewelry. Ancient thieves robbed the pharaohs of their wealth. Modern thieves have come for the pharaohs themselves.

It's really just a security problem. Once you dig something up, you have to guard it. And it's a lot easier to guard a hundred mummies in one museum than it is to guard a hundred mummies at a hundred different tombs scattered throughout the countryside.

Sure, you could just say, "screw it, no more archaeology, we're just leaving everything in the ground!" But then again, thieves can excavate tombs just as archaeologists can. And if you never reveal the ancient secrets, if living people never get to see these ancient mummies and artifacts, practically that's little different than letting the treasures be looted. Morally I'm not particularly concerned about disturbing ancient graves. I don't believe in ancient curses, or that we will be disturbing the real afterlife of a pharaoh by doing whatever we want to his corpse. To me these are just inanimate objects. Their worth comes entirely from the value they have in the present and future as the cultural heritage of the Egyptian people (fuck the British Museum). An artifact left forever in the ground, never again to be seen by living human eyes? To me that has no more worth than any random rock.

Living human beings are what provide value and worth to inanimate objects, even if those inanimate objects used to be human beings. I don't support looting recent graves or the ancient burials still revered by modern people (like ancient Native American burial sites.) But if the actual living indigenous people are OK with it? If they're the ones leading the effort? If we're not going to hurt any living people by digging up an ancient tomb? I'm all for it. Graves are for the living, not the dead. If it wouldn't cause pain to my own friends and family, I would be completely OK with someone just chucking my corpse in a garbage bin after I'm gone. I don't need it anymore. To me, it's literally trash.