lets pretend that teleportation (ie breaking down and transporting particles and reconstructing them in the exact manner) is possible. how would they teleport something living?

life is not merely a collection of precisely arranged carbon, hydrogen, oxygen, etc particles. what about intangible stuff like memory, identity, etc?

therefore, the teleportation envisioned in sci-fi shall remain as they are -- fiction

true, but this fiction require significant progress in a lot of other field to achieve. ie, you have to answer what is life and soul first. teleporting inanimate object is a more realistic (as if any of those popular sci-fi is "realistic") goals

we do have some success in pseudo-teleportation of small particles. IIRC they instantaneously created same particle at B while destroying the original at A. so you have the effect of teleportation but whether its really teleportation or not is up to debate.