I was looking at cheap USB hubs and realized that a lot of those have 1 Gbps Ethernet port these days. That practically means those are external network cards that can add a new network interface to devices, whether a computer already has it or not.
If people are using server-focused operating systems, it's also possible to bind those extra network cards together to add more failure tolerance to the connectivity. That way same computer could be using several Ethernet ports at the same time to speed up the file transfers and connect to multiple network devices at the same time.
At the same time, cheapest 2.5G (2.5 Gbps) Ethernet cards are around ~18,90 € for internal PCIe slots. USB-A connected 2.5G network cards are 20,90 €, while more modern USB-C network cards are a bit more at 21,90 €. Those essentially provide more than double the speed compared to 1 Gbps network connections, but your local switch has to support them to benefit from the increased speed.
Anyway it's good that there are more options for upgrading older computers to improve connectivity. What is good also is that those external network interfaces work on most regular computers, regardless of the operating system.