1. Harmonies
ISTG, they have the best harmonies in their songs. They are the pillars of any EXO song. And it's only possible due to EXCELLENT VOCALS. Different voices working together and the BLEND they have is just NEXT-LEVEL.
2. Balance
Production in EXO songs is always balanced. It doesn't overpower the vocals, and the vocals don't overpower the instrumental. There's only one song in which instrumental is slightly overpowering :- Going Crazy.
3. Phrasing
This enhances the songs like no other. Special shoutout to Kyungsoo and Baekhyun.
4. Dynamics
"Dynamics are an important way of conveying the mood of a piece and the use of dynamics is a marked element of the performance."
This is exactly what I am talking about.
5. Choice of Producers
This is also important. Some of the best composers in KPOP :- LDN Noise, Kenzie, Bazzi, Adrian McKinnon, MZMC, The Stereotypes, Tay Jasper, Dem Jointz etc
Especially LDN Noise, They produced so many EXO masterpieces like Lucky One, Monster, Ice Queen (from Baekhyun's City Lights), Butterfly Effect, Gravity, Power, White Noise, Forever, Lightsaber etc
Above are the few of the many reasons why EXO has superior music. I think everyone should check them out regardless of if you listen to BGs or not...... One of the best discographies of all-time. You won't regret it.