What are these blue structures inside the Pyramids in Sumeru? I also found them once outside while flying. Can I bypass the structure in 2nd pic to get the dendroulus?

Deshret experimented a lot on light based constructs. This is why there are lots of puzzles involving light and creating objects thru light in the desert. If you cant seem to bypass the puzzle it might be part of or unlocked by a world quest. Basically you get a tablet in one quest which can have its security clearance upgraded through other quests, allowing you to do puzzles you couldn't before.


It's basically the scifi concept of "hard light".

The blue tiles are part of the puzzle as a invisible floor. For any of these you come across there is a way to navigate through/around them to get to whatever treasure they are blocking.

So just look carefully and you'll eventually find your way around

Footholds nothing much, they are just invisible paths set up to Solve puzzles..
There's a lore behind it, the other comment has mentioned it.