The reason Lee Seung-chul revealed he is envious of his juniors, BTS

It is interesting that Lee Seung-chul, celebrating his 40th debut anniversary, mentioned BTS as junior artists and said he envied them. It feels unique that a senior artist who has been active in the music industry for a long time expressed such feelings while looking at BTS's activities and achievements. It is especially meaningful that this conversation took place while preparing for the 40th-anniversary album, and I am curious to know exactly what aspects Lee Seung-chul said he envied.