That though is pretty neat brickwork, all lines even, all blocks fully seated and all joints are levelled off. Takes skill to do that, especially on an unplastered wall. Paining though will be an issue, you need a rough surface roller, and at least 3 coats to get a coat that will not show all than the worst imperfections, or learn how to bag wash the wall to get a plaster layer over them to make a smoother surface.
Here though those walls would be put in after shuttering and casting the floor slab above, not as part of the support structure during casting, along with it being a load bearing structure.