I am an FO at a legacy carrier as well. In a similar situation with 15+ years to a short haul command.
I had a few drinks with an EK 777 FO two nights ago.
He left a legacy carrier to join EK and has regretted it since the day he joined.
he says EK is hell. flying 90+ hours on average. His family takes strain and he is always tired.
I'm staying put and I suggest you do as well.