Thor Ragnajoke introduced one of the greatest mysteries of all time into the CBM Forums and that being how in the hell did Hela destroy Mjolnir? It has been debated to be pure strength, that Hela shouldn't logically have. And magic that Hela has shown next to none amount of sorcery. Just how powerful would one have to be to destroy this metal? Now with Endgame we finally have a clear cut answer with Scarlet Witch vs Thanos.
Sure there is no confirnation that Thanos' sword is Uru but it has to be. It's pretty much believed by all that Uru is superior to Vibranium and we see him shred Captain America's shield like it's not even there. That same sword also stalemated Stormbreaker, previous statements from officials even said that Thanos' sword would be a match for it. So of it isn't Uru, it's a comparable metal.
Scarlet Witch is a powerful telekinetic who can manipulate items in excess of thousands of tons who works on a molecular level, allowing her to damage vibranium as well. She chipped off a piece of Thanos' "uru" sword after a few hits so this gives us a basis of what is required to actually destroy Uru like Hela did.
Through scaling we can concur that it takes immense strength along with some sort of psychic manipulation, both of these women have that. Hela's power being special enchanted Obsidian manipulation that's comparable to Uru along with psychic control over them and minimum magic. So she has a link to Uru and a degree of molecular manipulation just like SW. She even crafted Skurge Uru Armor using nothing but her mind. Combining that she could squeeze Uru and destroy it's integrity much like Wanda did to Thanos' sword and when she destroyed Ultron.