Unlike Humans, the great Apes have feet with an abdicated big toe. This allows them to grasp tree branches and manipulate objects like we do with our hands.
My question is this: If an intelligent, bipedal humanoid retained this feature, what would their shoes look like? Would they even be able to wear them at all?
We already have some kind of shoes (o socks) which have room for individual fingers.
I imagine for your imaginary feet they would look like these, with the obvious adaptation of moving the toe on the side.
However, considering how cumbersome is to do precision work with hand wearing gloves, I doubt that ape feet (which are meant to do precision grabbing) and shoes can coexist.
Thicker padding on the walking surfaces and fingertips.
When an ape walks (on all fours) these are the surfaces of the back feet in contact with the ground. Your shoes should be a pair of fabric gloves with hard plates on the walking surfaces.
The shoes still do their job, and the fingers/toes can still be used for climbing if necessary.
So as to get a permanent upright twofeeted walking whilst keeping the handly setting, from a speculative evolution perspective, I recommend to lengthen and strengthen the metatarsal bones and become the apes or any other unmannish primate lineage into metatarsigrade walkers, right like the birds and other theropod dinosaurs, but only when they themselves are on the ground; otherwise, when they're on a bough or hanging from a bough, they'll be plantigrade walkers. That's how my sophont lemurs's feet are. I also happened to design Romanly sandals for my lemurs's feet, which have individual slots for the toes, and are full of adjustable straps: 3 straps for each toe, 2 straps for the feet's rest, and 2 more wrappings for the ankles. These sandals's paddings are thin yet sturdy and bendsome, akin to the mannish “barefoot shoes”, since they must still enable delicate toe movements for handling little objects.
