I think geometry problems are well known to be very easy for machines relative to humans. See e.g. here. So this doesn’t seem like most of the difficulty.
We call this chapter “Geometry for Americans” instead of “Geometry for Dummies” so as not to offend. The sad truth is that most mathematically inclined Americans know very little geometry, in contrast to their luckier peers in Eastern Europe and Asia. But it is never too late to learn. Geometry is a particularly fun topic to study, because you are compelled to draw lots and lots of pictures.
Is the imo grand challenge plausibly solved or solved soon?
I think geometry problems are well known to be very easy for machines relative to humans. See e.g. here. So this doesn’t seem like most of the difficulty.
Though perhaps it is a subset of humans:
(30% serious here)