Thanos could do everything H/P Doomsday did physically (other than the freaky mutations). People might be offended by the notion of Thanos wrecking Darkseid in only a few shots. But H/P Doomsday caught him off-guard almost completely. Peers can wreck each other in a few shots when they're caught off-guard completely. It's happened too often in comics to ignore, e.g., Captain Marvel two-shotting Superman with suckerpunches, Thor putting a hole right through Angrir from behind, Surfer wrecking BRB after a board-shot to the back of his head, etc.
In other words, Darkseid would have done better had he not been so supremely confident in himself to just walk away and turn his back. By the spirit of the thread, he gets placed in the exact same position H/P Doomsday was in. Which was inside rubble after being Omega Beam'd, and bursting out when Darkseid's back is turned and being able to pounce on him when he's off-guard.
He's levitated plenty of times. He doesn't really soar around like Superman. Anyway, H/P Doomsday can't fly, so does it even matter?
Just want to add to my point, I don't recall DS getting sucker punched to KO in any other fights. There are tons of fights where he gets blind sided even by superman but HP was the only one that came close to killing him with that tactic. If there is no other event of DS getting sucker punched to ko we can't assume that thanos can do the same.
It was the writer's intention that HP DD>>>>>>>>>>>>>>>>>>>Darkseid. The whole scene with statements said points to it.
When CM, Surfer, etc. did the same thing it wasn't the writer's intention to show that they were>>>>>>>>>>>>>>>than their victim. Those were legitimate sucker shots.
Lastly, Thanos is not as strong as DD as he is not as strong as Superman. Also he is not as fast nor has bony protrustions. So he couldn't have manhandled and sliced up Darkseid like that. His blows would have been less powerful, his speed much less (Darkseid can recover quicker), and no bony protrusions to cause greater damage.
How would you compare Thanos durability to those missiles?
Can Superman with all his might damage Thanos at all?
He couldn't damage those missiles using all of his might.
And a half power the OB vaporized the missiles.
Imagine at full power how Thanos is going to fare.