I have a TP-Link Archer USB 802.11ac Wifi USB stick. It definitely does not work out of the box. You have to get and compile some driver from GitHub using dkms. After some stable Ubuntu updates Wifi just stopped working.

Never had a problem with macOS Wifi since 10.5.x.

You need to check the chipset before you buy. Intel and Atheros have a good reputation for Linux support. Broadcom does not. I heard broadcom is leaving the wifi market soon. If so, this should get better in short order.

The thesis was that Wifi is simply not a problem anymore on Linux, which is false. Wifi is not a problem if you pick the right chipset. However, this has always been true. I was using Wifi without a problem more than a decade ago, when Intersil Prism (Orinico) was very well supported on Linux and BSD.

But it's currently not the case that you can take an arbitrary Windows or Apple machine, install Linux and have a working Wifi. It's very much hit and miss.

The remaining holdout with problems is Broadcom. All other chips (Realtek, Ralink, Atheros, Intel to name a few of the more popular) generally work.

The only trouble you may get is with cutting edge hardware because manufacturers are slow.

FYI: the TP-Link Archer that I mentioned uses a Realtek chipset. It does not work out of the box. You have to get an untrusted driver from GitHub, compile it with DKMS. Breaks with stable Ubuntu updates. The driver also seems to be quite flakey, regularly losing connection to the AP.

How do you expect a normal user to this?

I really don't understand why there isn't a niche company that does nothing but make high quality peripherals that work in Linux. I just bought an atheros wifi card off amazon marked ENGINEERING SAMPLES ONLY, because no one sells the chipset I want standalone.

Intel chipsets are OEM only. Cards are readily available on Amazon, but are all gray-market apparently.

In short, I don't expect normal users to do this, but I'd expect them to be willing to pay triple the normal markup on $20-$50 componens if they "just worked" in Linux.

To be clear, I'm talking about having an ODM run off copies of Intel/Atheros reference boards. The engineering effort is as low as it gets for hardware manufacturing.

The only wifi device I've had trouble with in recent memory is an Edimax EW-7811Un USB dongle. It "works", but the best transfer rates I've ever gotten out of it were in the hundreds of kilobytes/s, paired with up to 5 minutes of uninterrupted connectivity.

There are problem devices out there, but more and more they're the exception, rather than the rule.

Which macOS version is that?

I stay up to date, it's 10.12.2 - I've had the issue for at least a couple of major (marketing) versions.