Actually, the Thunderbolt 4 trademark on a cable IS a guarantee of quality, data rate, and power transmission! Intel tests and certifies the cable meets design requirements, and then they audit these cables in the field to make sure they continue to do so through the production run. As far as Speed goes: all TB4 cables are 40 Gbps. For power, all TB4 cables are 100W (5A) capable.

Note: at some point soon, all TB4 cables will be 240 W capable, I just don’t know when this will occur… it is a newer Type-C spec.