Recently retired hardware:
Many years ago, computer motherboards arrived without a wired network card because networks were changing too fast. You bought your own card and occasionally replaced it with a newer model. With motherboards now featuring a standard Gigabit wired Ethernet port, you might buy a card to get a second port.
Wifi components are going through the rapid evolution Ethernet once endured. You are more likely to add or upgrade Wifi. Modern USB is faster than Wifi and the easiest way to add Wifi. After reading this article, you should look for a solid reliable USB Wifi device.
Wired networks are slow at just 1 Gigabit. There are now options for 2.5 Gb, 5 Gb, and 10 Gb. 2.5 Gb and 5 Gb are possible using the right low cost Cat 7 wiring. Some brand new motherboards have 2.5 Gb on board. If you are setting up a new wired LAN, 2.5 Gb is the minimum and you can upgrade old computers with an expansion board.
For existing networks, you can reduce traffic by offloading things like backups to a second network. You add extra Gigabit cards and the right wiring. Motherboards designed for servers will often have two Gigabit ports as standard and may have up to four. My junk bin card would be useful for this if I was not using Wifi for the second network.
The GA302T card contains a shielded socket for the Ethernet cable, a big chip to drive the Ethernet port, and a big heatsink. The chips used to be big because Ethernet uses different voltages. The card/chip contains circuits to develop the right voltage. On a motherboard, the different parts of the process can be spread over several support chips, removing the need for a monster chip.
Ethernet speeds of 2.5 Gb and up require more extreme power, forcing you back to monster chips. The 2.5 Gb speed is just starting to reduce to something you can have on a motherboard. The 2.5 Gb add on cards look like the early 1 Gb cards with a big chip and a big heatsink.
Often new computers arrived with faulty Ethernet setups. I could add in my Ethernet card, connect to the network, and download the right driver for the substandard Ethernet chip in the motherboard.
Many Ethernet chip + driver combinations rand below the advertised speed. I plugged in my known card to measure the actual speed provided by the network.
When you have problems, you need a known card, well tested cables, and often a reliable Ethernet switch to eliminated flaky components in the network. I carried all those items and made sure everything was solid, not the cheap plastic you get now.
Wifi fails net to microwave ovens and almost everything electrical. I worked in warehouses, factories, and offices where the electrical spikes from machines produced constant dropouts. The current 2.4 and 5 GHz bands are flooded in cities and inner suburbs. Both will get worse. The new 60 GHz band only works over very short distances. Everything metal blocks Wifi.
MIMO is the minimum standard for Wifi but costs the brand owners a few extra cents when Foxconn manufactures their product in China. Big corporations ignore MIMO as it would mean one less corporate jet. When you do get MIMO listed on the box, you often do not get a real usable MIMO.
I currently run a wired LAN between two buildings as Wifi does not work over the distance without special expensive directional microwave antenna. If I did set up the antenna, the metal in other buildings would block most lines for the microwaves. I would have to run wired networks up to high mounted antenna. It was far easier to run a cable in a pipe in the ground.
Wireless is limited by available bandwidth less all the bandwidth lost to interference. There are only two bands that work at any useful distance. You can stuff dozens of Ethernet wires in a cheap plastic pipe. Wired wins at ground level and within easy to maintain buildings. Wired is really only a problem when you rent, which stops you drilling a few holes, and in historic old buildings where the slightest work requires massive committee meetings and expensive permits.
Wired is predictable, it does not drop out when your neighbour streams a movie.
Wired is a one off installation for fixed position computers like desktops and servers. The config work is not much different to wireless config and is often easier.
The Netgear GA302T Ethernet card always worked, saving me dozens of hours on each of many projects. Using a low old hourly rate, the card saved me way more than $20,000. The old card is out. I am now looking for a solid reliable Wifi equivalent to put in my toolkit.