What's the case for Thunderbolt not just being USB 3.2? Now that it's using the exact same connector, it really seems like a solution in search of an actual use

What's the case for Thunderbolt not just being USB 3.2? Now that it's using the exact same connector, it really seems like a solution in search of an actual use-case. I thought the external GPU thing would be amazing, except that totally failed to materialize, and I've even heard that it's being actively blocked.