Hey man, I don't work in these companies but I have friends who do, if you don't mind, I'll share their experiences with you.
The 996 culture isn't true for Singapore, yes I know people at shopee OT a lot, some even come on Weekends but it's not a MUST. That needs to be cleared up...
As for the pay, Bytedance pays above 6k with 0 YOE. It's true, I have a
NTU grad friend who got it. For Shopee it depends, not all SWE get 6k or above 5k. I have heard of people getting 4.5k.
Sorry I can't give you any more info than that, none of my friends will share their TC, only their base pay with me...
So yeah if you have the chance, go for Bytedance definitely. The pay is amazing, WLB is not that awful tbh, I'd say it's similar to DBS. ( Some OT, etc )