If you read the article than you'd understand it's about degree of discount to which two or more passengers are receiving. In some cases two tickets is almost as cheap as one ticket. If these prices converge it would actually make sense to buy two tickets for one traveler if you value comfort and can afford it.
Part of what makes it seem shady here is that airline ticket prices are pretty opaque. If they advertised it as a group discount, it would be received differently.
Airline pricing in general is pretty opaque. Not hospital pricing opaque, but still pretty opaque. It's one of the few things we regularly purchase where the price changes almost daily (both up and down). For example, bus and train tickets are pretty much the same price each day for the same route. For airlines, I'll often check the price on some future night to see if it is cheaper or not.
Like medicine, the price is a negotiation point in a complex web of probabilities. Air travel can be more transparent because the probability network is simpler and the spread is narrower, but they’re both dealing with realities of providing predictable service under volatile demand and group payer conditions.
Distance train at least may (or may not depending on location/country) be quite a bit cheaper for advance purchase but maybe doesn't fluctuate as much day to day.
Maybe even if it was a possibility before, it wasn't used and now airlines have enough data and market power to actually make different prices for groups
(By the way, if it's about inflating prices for individual, then it's not really volume discounting... it just appears this way on the outside)