This is one of those things I didn’t know I needed.
It’s the 2.5Gbps USB Ethernet Adapter by Plugable (link in bio).
I have 1.5Gbps speed internet at home, but I was only ever able to achieve 1 Gbps speeds plugging an ethernet cable directly into my Mac Studio. When I switched to a MacBook Pro, I was limited by Wifi speeds of about 500mbps.
Recently, I wanted faster upload speeds so I got the Belkin ethernet adapter offered at Apple. While I was troubleshooting that on Google, I found people talking about this adapter by Plugable so I got one out of curiosity. I also had to troubleshoot it as it was disconnecting continuously, but updating to the latest version of Mac OS solved any issues.
Now I’m getting the full speed of my internet plan, which is awesome. My upload speeds are the same though so if you want to save $7 and are just looking at increasing your upload speeds, the Belkin adapter would work just fine.
I tested this with the USB-C to USB-A adapter that it comes with, but got significantly lower speeds in the 150-200Mbps range. Of course, to test this I had to use a USB-A to USB-C dongle so it may not be this much slower if you’re going directly into a USB-A port.