WhatCable looks handy (seen via DenseDiscovery):
$ whatcable
=== Port-MagSafe 3@1 (MagSafe 3) ===
Charging · 94W charger
Power is flowing. No data connection.
• Charger advertises up to 94W
• Currently negotiated: 20V @ 4.69A (94W)
Charging: Charging well at 94W
Charger and cable are well-matched.
=== Port-USB-C@1 (USB-C) ===
Slow USB device or charge-only cable
Only USB 2.0 is active. If you expected high speed, the cable may not support it.
• USB 2.0 only (480 Mbps), no high-speed data
• No e-marker detected. The cable may have one, but macOS only reads it above 3A or with Thunderbolt.
Connected devices:
• Apple Watch Magnetic Charging Cable - Full Speed (12 Mbps)
=== Port-USB-C@2 (USB-C) ===
Nothing connected
Plug a cable into Port-USB-C@2 to see what it can do.
=== Port-USB-C@3 (USB-C) ===
Nothing connected
Plug a cable into Port-USB-C@3 to see what it can do.
Pro features: charging diagnostics, negotiation tracing, liquid detection. Run whatcable --pro for details.