That sounds pretty terrible. In terms to auth speed we get that occasionally in very small stores (newsagents) but when you have to type in your PIN most stores handle it all in a few seconds now. The 15 second auth time was common here until about 5 years ago. In the last year I've also seen massive improvements, largely due to stores upgrading terminals to support contactless payments which I use almost everywhere now. I regularly leave home without my wallet as I can be quite certain I'll be able to use Apple Pay via the contactless terminal.