Is sagging facial contour caused by the shape of the face rather than skin elasticity?

But I'm still in my 20s, so my skin doesn't seem to lack elasticity... This and the side effect of sagging are unrelated, right? ㅠ
 I lost about 20kg just by exercising this year, and my face didn't sag even though I lost it quickly... I wish it could stay like this even if I get surgery... I always sigh while touching my chin.
 
When I look up body contouring stories, everyone says they get surgery even
 if it means saggy cheekbones. ㅠㅠ Of course, I'm not not thinking about that... Even if the flesh sags a little, I think it'll be better than living with my current cheekbones and square jaw, so I'm going to get it done! ㅋㅋㅋ But
 
if it gets too bad, I think it'll be stressful in its own way, so I'm still worried...ㅎㅎsighㅠㅠ