Do K-Pop Idols not sing live anymore?

On May 14th broadcast of Music Bank NCT Dream had their comeback for "Hot Sauce" as well as their b-side track "Dive into You".But during the performance audience noticed that Renjun was not wearing his mic and yet everyone was able to hear his voice. This clearly showed that the whole stage was pre recorded and that the group wasn't singing live. This has happened before with many other K-pop groups including Twice. What do you think about K-Pop Idols lip syncing.It sure is difficult to sing and dance at the same time but they are singers after all and people want to hear them sing live and not hear what they recorded in a studio. Which groups according to you does lip-sync?