Comment by fiber

This reflects only the peering capacity available for public peering and only what has been documented by each ISP for that network. Private peerings (that are direct connections to another network) are much much more cost-effective and easier to scale for a large ISP. In any case you can safely assume that DTAGs peering capacity by far exceeds one or the other Tbit, but it's also far from being sufficient capacity after all. They may also be the largest ISP in Germany by user count, while other metrics may vary ;).