Now take away the chore of 'focusing on riding'. Genetically or chemically calm the horse so it does not get flustered or moody. Metabolically tweak the horse so it does not get tired or thirsty. Robotically till and smooth the ground so there is nothing to trip over. Notify everyone in the vicinity where the horse is going, so there are no obstacles to avoid. When you can't crash or fall off if you try, when it doesn't matter if you're focusing or not. Maybe dynamically adjust that so you know the AI overlord is pampering you to keep the difficulty 'just right' and this is not a real challenge it's elaborate wireheading.

Your point 2 is where my onion metaphor comes in. When you fix a problem you improve a thing. When you fix all the problems you have taken all the life away from living. Maybe that works for what to do today - Ostrich head in the sand and solve problems - within our lifetimes, or even several lifetimes, but if AGI really does spawn and solve all problems immediately the head has to come back up. If AGI never spawns, we might still effectively solve all human-scale problems with the assistance of sub-human AI and brute-force within a surprisingly short time.