re: Did Min Heejin betray SM by leaving them for Hybe?

Soooo

Quote from OP

After she moved to Hybe, she rebranded Bighit into Hybe, designed their new building and now created NewJeans who directly compete with Aespa. Why couldn’t she stay at SM and help them the way she’s helping Hybe now, especially since she already worked at SM for 17 years?

Imagine youve worked for the same company for 17 years, overseen many of the debuts that honestly made your company the most powerful entertainment company in your country, and still nepotism is the only way that anybody is allowed to move forward in your company AND your aging CEO shows no signs of restructuring the business.

She was constantly shot down for trying to write/produce music because it wasnt her job and she got tired of it.

I would have left years ago

If by betraying you mean saving her life from dying burnout, I mean you are right.