Just look at the history of their DXF format, which was hailed as their way of enabling interchange, but has perpetually been under-specified and lagged way beh

Just look at the history of their DXF format, which was hailed as their way of enabling interchange, but has perpetually been under-specified and lagged way behind the AutoCAD internal DWG format. It's not like that was an accident, they don't want you to be able to reliably take your drawings somewhere else. You need to be sure that any conversions of engineering drawings are perfect, so they make it 99% compatible to tout interchange, while the uncertainty from that last 1% of coverage makes it questionably useful in reality. The CAD/CAM/engineering simulation industry in general is really bad - full of extreme vendor lock-in, onerous licenses and draconian DRM.