I pulled up the actual USB power delivery standard[1] USB_PD_R3_1 V1.8 2023-04.pdf, and 5V 5A is perfectly compliant, albeit optional.

On page 805 you find Table 10-2 SPR Normative Voltages and Minimum Currents, which specifies that a USB PD source with a rating of 15 < x ≤ 27 watts *shall* support 3A at 5V, however it *May* advertise up to RoundUp (PDP/Voltage) to the nearest 10mA. Requires a 5A cable if over 3A is advertised. 27W/5 rounded to the nearest 10mA comes to 5.4A

[1]: https://www.usb.org/document-library/usb-power-delivery