Why is "bioroide/bioroido/bioroid" used in different animes?
Bioroid is a word depicting a artificially created, cybernetic or biologically organism. Where the roid stands for android and bio for bio.

This term is mainly used within the sci-fi genres, one which is broadly covered by anime's as well.

So to to answer your question Why is “bioroide/bioroido/bioroid” used in different animes?

It is term used within the sci-fi genre to depict artificially created cybernetics.