USB-A, FireWire and that video output converged to Thunderbolt, which also means I can connect several displays to e.g. a 2021 MacBook Pro. The separate headphones and microphone jacks got merged as well. After the whole Touch Bar brouhaha, the card reader and HDMI also made their return.
So the one connector we did lose is Ethernet. Which, to be fair, is a bummer indeed. Luckily, we can easily push 1 Gbps over Wi-Fi nowadays.
I don’t know, since I didn’t have to specifically buy anything to get that throughput. So, in my case, it cost me nothing.
It was just an ISP-provided router and an older Mac Studio. I didn’t check but there’s a good chance the wireless link actually supports even higher bandwidth; at the time, I was bottlenecked by the 1 Gbps connection to my ISP.