hiii anon, I'm not really a professional vocal coach or anything, I just like to study vocal techniques, specially from musicals! so don't take my words too seriously this is just from my humble perspective!

I will only do 127 cause they're the ones I've got recent performances in my mind. it's been way too long since I've seen dream or checked any of their performances, and I barely know wayv or wish, so I can't do them either.

doyoung ofc would be first he's just way too good no explaining needed here.

haechan comes second. he's a very good singer, just not as developed as doyoung, and that's far from being an insult. he isn't as powerful and consistent as doyoung when it comes to stability, but he's good nonetheless.

jaehyun would be third imo. he's not as powerful as haechan and doyoung, nor can reach the same high notes as them, but he's a good singer and can hold himself pretty good. I feel like his biggest strength is how controlled and stable he is.

yuta could share the third spot. he's a very versatile vocalist, but I fear this is where fans starts to confuse themselves. he is able to reach high notes, yes, but that doesn't mean he has the technique to do so. he reaches notes and imo he has a powerful reach and good chest control, but he is nowhere close to being on main vocal level in terms of technique. this isn't an insult, nor degrading him in any way, just saying that he's not as well developed and that is important to acknowledge it because consistency is a key point to what makes a good singer, and he is one, but he doesn't have the consistency to do the same highnotes as doyoung and haechan, for example, in long and repetitive periods of time, like during a tour. if he did so with his current level he would ruin his chords.

jungwoo and mark are a fun case imo because they have opposite issues.

jungwoo is good at singing, but he's not so good with breath control. and I'm not talking about stamina in performances because this is a problem the 7 of them have, but general breath control. his tone is too full of air sometimes and that makes his enunciation of the words kinda too breathy? idk how to explain it properly but it's not a really good technique. there's songs like djj kiss for example in which you can see he sounds way better when he doesn't do that, but he does it more often than not. but overall, he's an okay singer.

mark, on the opposite, has a good control and very very good enunciation, he's just not very good at singing. he's not bad, but he's also not good. he's just 5/10 most of the time.

taeyong is very underdeveloped vocally. there's not much to say about him in terms of vocal (rap is a different thing) he's just severely underdeveloped. he can pass as an okay basic singer but that's it. he has good moments and he also has very bad moments, but overall, he can pass as okay.

johnny is terrible at singing if there isn't someone (usually doyoung) to balance it out it's just awful