Six years ago I bought one of those longer Lacks for ~15EUR and heavily use it close to every day. The black top varnish seems to get pretty thin at the most used locations which is the only wear marks I can spot.
I use it for eating, writing, etc. Maybe others have other plans to use a coffee table in a way that requires tougher structures.
I think lateral stresses (from people's feet, etc) did mine in. The seams failed, and things quickly deteriorated after that. A lot of Ikea stuff is designed with zero redundancy or design margin, so if any part fails or weakens the whole structure is compromised.
I use it for eating, writing, etc. Maybe others have other plans to use a coffee table in a way that requires tougher structures.