What actually makes a good singer is an interesting question.
>>202229 is all reasonable advice, but you can follow it perfectly and still sound boring. I've heard plenty of singers with perfect technique who I just don't want to listen to. On the other hand, there are lots of very 'bad' singers who do sound like something you want to hear.
https://www.youtube.com/watch?v=RLq7Aqd_H7g for example, Leonard Cohen is an awful singer technically speaking, however if you listen to one of the many covers of his songs by technically good singers, the songs just sound boring and you go back to listening to his original version. Other examples include Bob Dylan, Arcade Fire, Jimi Hendrix etc etc…
So it's hard to say what makes a good singer good. The best I can come up with is to only train your voice in order to, for example, not damage it in any way with bad technique, and otherwise focus on sounding interesting rather than 'good'.