I actually think your entire statement can be applied to both yang zi and wang yibo as well.

iao Zhan can sing yes, but not that powerful. He can act, but there's no impact at all.

His one of the very few chinese actors who has a presence in anything he does. Others are just like wooden figures in front of the camera, whereas he has this natural and humble charm.

As for acting sure , he's not the best, but his got the POTENTIAL to be the BEST. After he got famous, instead of taking a 110 easy romcoms his tried doing different roles out of his comfort zone.

In conclusion it probably boils down to preference with some people. However, Xiao Zhan is fantastic as both a singer and an actor thus far on the same level of wang yibo and Yang Zi as well. For me there's no difference here.