is TFT already dead?

I don't think it's dead, although I do know a few people who have stopped playing due to the LP system in higher ranks. Myself included.

You sure? Played a few over the weekend, got into them within seconds.

No. It is not "dead" because the mode is stabilizing.

When something is really super popular, the popularity drops after a while. It's not dead, it's just going to a normal level.

I think there are more folks spread out over more elos now which is increasing q time. At first you had a ton in the same area. Now that pool has slimmed increasing queue times. Sill a queue to get into the game at night so it's still pretty popular.

Nope, not even close to dead. People are just off the "I'm going to play every spare minute" train. And also, if you are playing normals most people may be playing ranked. If you are playing ranked there may not be enough people close to your elo playing at the moment.(Happens often in high elo & low elo games.)

yes. until they normalize item drops.