Titanium is one of the best for the application of medical implantation in the body but not the best material for the application of body piercing jewelry. Here's why.

If the application requires the metal to survive in an oxygen starved  harsh liquid environment, such as implanted within the body, to survive 10 to 20 years 316L  would not be considered the best for that application. If the criteria is only safe and effective in use there are many choices. For example, Gold, Silver, titanium and many other materials are safe and effective for the body piercing jewelry application.

Several materials are proven by use to be safe and effective over time for body piercing. Titanium is one such material. The Industry choice is overwhelmingly 316L stainless steel because it has a shiny appearance, low  cost, ease of manufacture, availability of product and though it is not as corrosion resistant as Titanium it doesn't need that high level of resistance for body piercing. Using these multiple criteria 316L is the best for the APPLICATION of commercial body piercing jewelry.

"Titanium Leaching"
"Titanium does leak from the implant, as evidenced by the occasional blackness of the tissue surrounding the implant. No adverse tissue effects have been demonstrated ... no evidence was found of any biochemical or hematologic toxicity ... Persistent dietary intake of the metal results in some accumulation in the heart, lungs, spleen and kidneys although no adverse effects have been observed ... "
from High Performance Biomaterials, Scyzcher, page212

For Tattoo charges of "toxic" tattoo ink because toxic particles can be detected  there is no evidence of any biochemical or hematologic toxicity.

For Piercing we can argue the same to support the continued use of 316L.