Own both. BF1 is garbage compared to TF2.
Why? Because for the most part in TF2, I can control the deaths I take. Obviously there will be times when you spawn at the worst time and place or get into a fight and 2 other enemies are with the one you just killed. But really, I don't have to put myself into any positions that will instantly kill me if I don't want too. I do it all the time regardless because I want to get to killing asap, but if I took different approaches, I can get around without being somewhat spotted and killed.
But in BF1, well the story in that game is just you getting fucked. All the time. Vast open spaces to be sniped. Check. Tanks all over the place to murder you. Check. Massive amounts of enemy players in all directions. Check. Try to hide andsfnasdkfalsdj building explodes.
So much in BF1 I feel I have zero control over. It never felt that as bad say in BF BC2. Maybe I remember it differently.
Regardless, I can't put these numbers up in BF1. But in TF2... seems to be a no brainer: