I had thought about it but perhaps this manga is older than current tech & hadn't looked into the year it first appeared. They still use flip phones too (when the kidnapped girl finally contacted her family & friends) but that's not to say Japan has abandoned the use of flip phones today. What I actually want to see is the use of drones for surveillance, shipping stuff or sending letters but that's still something recent.
That said, Yao's misfortunes were actually brought upon by her own thoughtlessness. It's not that she's truly unlucky but she just... didn't think anything through. She lacks common sense.