I hate to break it to you, but they've always been unfeasable.

...on the Earth. We could make a Moon elevator with currently-existing materials.

here's a good video on space elevators

the engineering challenges have been known for a long time now, but there are ways around it. there are also other technologies that are viable, some, like the skyhook, are most of the benefit but possible with current tech. others, like orbital rings, are straight up better but have a high upfront cost to build

this is my special interest, so ask away

its unfeasible because capitalists would definitely fuck it up and you dont want something that big falling down

Sky hooks are a far more feasible idea and do pretty much the same thing