Nope, according to https://opensource.com/article/19/6/raspberry-pi-4

> The BCM2835-based chip in Raspberry Pi 1 to 3 provided just one native USB port and no Ethernet, so a USB hub on the board provided more USB ports and an Ethernet port. The 3B+ added a dedicated LAN chip, which gave it Gigabit Ethernet, but this was limited to USB2 speeds. The Pi 4 has dedicated Gigabit Ethernet, and because it's no longer throttled over USB, its networking speeds are much faster.

"The Ethernet controller on the main SoC is connected to an external Broadcom PHY over a dedicated RGMII link, providing full throughput. USB is provided via an external VLI controller, connected over a single PCI Express Gen 2 lane, and providing a total of 4Gbps of bandwidth, shared between the four ports."

Better than one could've hoped!!

Nope, it's completely unfettered by USB this time.

Possibly, but usb3 is a lot faster.