Yeah, this is the downside of chipboard: it's only kinda-repairable at best.

Wood glue + pressure is a good first step. Wipe the edges carefully to minimize seepage out the edges. After it drys you can rub a dark brown crayon around the edges to get wax into any visible seams to hide them.

To reassemble, you'll want to consider if you can use something like T-nuts. Or, as the other poster suggested, something stronger behind that you actually screw into. Consider that if this part was this weak, probably so are any other similar attachment points. So maybe while you're at it you could reinforce other places similarly.

It's a question of scale - there might be one sewer pipe repair per person per... decade, I'd guess? Actually probably way less, but let's stick with per decade.

Whereas there is one load of laundry per person per... I'm guessing per week-ish? And this probably pales in comparison to tires and brake pads.

So laundry is done something like 500x more often. Sure it's great to study everything, but it's also important to keep in mind what is significant and widespread, and what is relatively minor.