A recent article about how Bitcoin Core is not usable as cash:
Actually Bitcoin Core could still be digital gold 2.0, as some people say. You just need something to transfer it to cryptocurrencies that can be used as cash, such as Bitcoin Cash or Dash.
I tried https://sideshift.ai/ a couple of times and it worked really fine.
The author of the article might have used SideShift AI or maybe https://local.bitcoin.com/
Furthermore, he might have use MarcoCoino https://marcocoino.bitcoin.com/ to get somewhere that let you pay with Bitcoin Cash.
All in all, it's no surprise that there is no mention in the article of the Lightning Network.