Your world position solution is about 1/3 of the way there. You’re reinventing a technique known as tri-planar mapping, or world aligned textures.
The issue is you need 3 projections to solve the stretching.
RG is top down, but you also need RZ, and GZ for the side projections, and a blend weight mask to apply them in the right spots.
There is a pre-built node for world aligned textures. It’s not great, but it should be enough to get started. Eventually I would encourage you to make your own to fix some of the problems.
Here’s a good channel that has a few videos on the topic.
