It’s not a technical issue, but price is important when putting the networking techs head to head, particularly because it’s mesh networking’s big downside. For all the “just grab another node” arguments, that’s rarely a cheap solution. In fact, it’s often as hard on the wallet as picking up a whole new wireless router, because in a sense, that’s what you’re doing. If you’re in a smaller home, a single standard Wi-Fi router is probably enough, so you can steer clear of more expensive mesh packages anyway, and if you’re lucky, your broadband connection comes with a router. It might be shoddy, but you’re paying for it anyway. That’s a sunk cost.
Ethernet can be cheap, particularly if you’re prepared to wire it yourself, but installing it with professional help is far from inexpensive. That said, a good backbone will last you; line up Cat 6 cable, and you’re prepared for future speed upgrades either end of the wires, something that isn’t true for either of the wireless solutions. With 802.11ax on the horizon—expect early hardware this year, and realistically adoptable gear in mid-2019—a big investment in mesh right now might soon sting if you’re trying to stay cutting edge. Winner: