Vince makes up his patch cables using solid-core wires. Cables with solid-core wires should only be used as structured wiring. I.e. Fixed in position, by cable clips, by staples, in trunking, in conduit.
Patch cables, by the very nature of their usage, should be flexible. Flexibility by virtue of the usage of stranded wires.
An xDSL signal (be it G.992.1/G.992.3/G.992.5/G.993.2) is a radio frequency signal, constrained to the wires in the cable. The cables should not be thought of as a pair of wires carrying DC or very low frequency AC but as radio frequency feeders.
The higher the frequency, the bigger the skin effect, the greater the attenuation. At a particular radio frequency, which cable shows greater attenuation? That consisting of: (1) a pair of solid-core wires or (2) a pair of stranded wires. (In each case, the total quantity of copper used in each wire of those two cables is identical.)