halacha - What happened to the Jewish practice of using burial caves?

A three-part question about funerary practices.

In ancient times, Jews used to bury people for a year or two, then, after the body decomposed, collect their bones and put them in a family cave. In antiquity, the bones were all placed together, but later on, the bones were collected into ossuaries and the box was put in the cave.

• Why did this practice stop?


• When did this practice stop?



• What limitations (halachic and otherwise) are there on reinstating this practice?