The reason is probably that anything faster than USB 2.0 (480 Mbit/s) and supporting power over 3A/60V will need to have an active marker, and to read that, you'll need something slightly more complex than a connection tester.
That said, these things do seem to exist at this point, as sibling comments have pointed out.
As an aside, it's a real shame devices with USB-C ports don't offer this out of the box. They need to be able to read the marker anyway for regular operation!
That said, these things do seem to exist at this point, as sibling comments have pointed out.
As an aside, it's a real shame devices with USB-C ports don't offer this out of the box. They need to be able to read the marker anyway for regular operation!