Everything defined in the Thunderbolt 3 spec was incorporated into the USB 4 spec, so Thunderbolt 3 and USB 4 should be basically identical. In reality the two standards are enforced by different certification bodies, so some hardware manufacturers can’t really market their compliance with one or the other standard until they get that certification. Framework’s laptops dealt with that for a while, where they represented that their ports supported certain specs that were basically identical to the USB 4 spec or even the Thunderbolt 4 spec, but couldn’t say so until after units had already been shipping.
Things are muddied a bit though because USB 4 has built in support for thunderbolt
Everything defined in the Thunderbolt 3 spec was incorporated into the USB 4 spec, so Thunderbolt 3 and USB 4 should be basically identical. In reality the two standards are enforced by different certification bodies, so some hardware manufacturers can’t really market their compliance with one or the other standard until they get that certification. Framework’s laptops dealt with that for a while, where they represented that their ports supported certain specs that were basically identical to the USB 4 spec or even the Thunderbolt 4 spec, but couldn’t say so until after units had already been shipping.