Yepp, unfortunately true. Used to get LHR-DBX-SIN for GBP 380 return last year even during peak season throughout the summer. If a flight was almost full you would still get it for say GBP 480 (and there was no offer during that time).

Now, they want GBP 823.90, that is almost twice as much! Insane! And yes, those flights are still entirely empty if you look on seat counter or expertflyer.