The entire USB power situation is complex. Lets see, there's pre-enumeration classic 5V/100mA, post-enumeration 5V/500mA, a host of proprietary signaling methods for additional power, the more or less de-facto BC 1.2 method for extra power, Type-C analog signaling for 5V/1.5A or 5V/3A power, and USB-PD digital signaling. Oh, and there's also Type-C VCONN power in addition to VBUS power.

The irony in all this is that Type-C analog signaling was meant to greatly simplify the market situation and UX well above and beyond what happened in the micro-B charger world. And it is simpler. RPi4 just goofed in their implementation.