Found it on the curb, and I liked the design. Looks like solid wood, but the joints are all coming apart and look tricky to reinforce. Would you bother?
Haha it wasn't sturdy when it was new, what a design. I guess it'd be okay for small children (reaching sink to brush teeth, that sort of thing.). I'd still reinforce because that one time an adult steps on it's gonna bear trap their legs.
That said, this would be super neat as like a planter holder or something - pure decoration. A fresh coat of something to make the character lines pop. I'm amateur as it gets and would probably varathane it lol so don't ask me how.
I like the look of it too. But even if the bottom step were a single piece of wood, that's a bad design. If you support that bottom step under the riser and from there to the front, maybe. Best be lightweight.
If you have the time there's no harm, but you're probably going to want to disassemble the steps to repair it halfway well.
Depending on the weight of the person/people who will be be using it, you might want to rethink the design or make the steps out of something thicker/beefier. Since the two treads are essentially cantilevers, the riser and torque is all that's prevent the far end of either step from collapsing. I don't think a butt joint is good enough here, even if it has a backer (as the pictures show). A finger joint between the treads and the riser, with many smaller fingers, is probably your best bet. You'll probably want a table saw and a jig/slead to cut them, unless you're familiar with a good alternative and/or have the skill and time to do it with hand tools.
I think this is made from an exceptionally hard wood. It looks a lot like walnut or pecan. I would be concerned about cutting across the grain with a powered saw causing chipping and ruining the piece. I think I would repair the current joint and add a center leg or probably a leg on both sides to support that joint.
As someone who isn't a woodworker, but enjoys having things that make me happy- if you like the design and it makes you happy, go for it. You have nothing to lose but time, and if you learn something in the process (i.e. those tricky looking joints you mentioned) then you are ahead no matter what.