Yes their MDF is terrible, but also their plastics are inferior polymers that don’t age well. Some metal furnishings are sheet metal thin and lack structural rigidity/strength as well.

Obviously they make compromises to meet a price point, so given the price points of these products I believe they well lean heavily to the Ikea quality rather than Legos quality.

I would almost say if people have kids it’s maybe an option since they’d grow out of it, but then engineered wood would have lots of chemicals in them.