The past few years has seen some phone companies ditching the headphone jack in favour of a USB-C/Bluetooth combo. To make up for the fact USB-C headphones aren't very common, and some people might have issues with Bluetooth, companies have been throwing in USB-C to 3.5mm adaptors in the box. HTC isn't like most companies, and doesn't seem to be doing that with the upcoming U12+.
The U12+ was announced last week, with HTC confirming that the phone wouldn't be coming with the standard 3.5mm headphone jack that everyone is so accustomed to. While the phone itself will come with a pair of USB-C earbuds, the 3.5mm adaptor will have to be purchased separately for £9.90. They're also sold out on the UK and US stores, which is more than a little irritating, especially since, as The Verge points out, the adaptor that shipped with the U11+ was terrible and only worked with HTC phones.
It isn't difficult to find a USB-C to 3.5mm adaptor, nor is it difficult to buy an adaptor that adds Bluetooth to your old headphones, but this still comes off as a dick move. Especially if the last adaptor was so bad, and now nearly impossible to get hold of. Ditching the headphone jack is still somewhat risky, despite Apple's great success at continuing to sell iPhones in the aftermath, and the least HTC can do to ease the transition is throw in an adaptor so people can continue to use the equipment they already have.