The reason it was never salvaged is because the majority of the cargo consisted of Japanese silk products. When the ship broke in two, all of this cargo was ruined. Some was saved before she broke but not much. What remained was not worth the trouble in trying to salvage. That would be about 200 tons of Manganese Ore used as ballast.
However, in the early 1990's, for some reason, a story came out about the Sindia possibly containing stolen Buddhist temple artifacts in place of the Manganese ore. A bit of speculation that makes no real sense.
Here is a ship whose captain and crew were taken off safely. Which is beached and buried. Why do you think that there were no salvage attempts between 1901 and 1995? Because there is nothing to get.
In 1995, the rights to the wreck were purchased by a group of investors who planned to spend $5 million on the recovery of this imaginary treasure. The rights were put in the name of Dennis J. Parisi, president of Drexel Aqua Technologies, Midland Park, NJ.
Obviously, it didn't pan out.