Maybe someone who knows electronics better than me can chime in with corrections and/or correct terminology, but my impression is that USB PD doesn't lend itself to having a bunch of type-C ports that draw from a shared max power rating in the way that's common with USB BC devices. e.g. if you have a 100W brick, you're going to have five ports with 20W max, or one 60W port and four 10W ports, etc. (that is, each port is essentially an independent charger sharing a housing, and with the heat limitations of the shared housing)

The USB-C PD definitely allows you to do exactly what you suggest.

I know this is supported in this google dual-port PD charger: https://store.google.com/gb/product/usb_c_dual_port_charger

There is an explanation on how the power budget is split in this post: https://plus.google.com/+BensonLeung/posts/8jmUYtJxAwX

Presumably other multi-port chargers also do similair things

This is pretty close to what you're looking for, except with a single 87W USB-C PD port and 4 12W USB-A ports: https://www.amazon.com/gp/product/B07DGTFQTD/