Well that was a tranporter accident implying the results would be difficult to duplicate. Furthermore it's likely that Federation law would prohibit such a use of technology. In a world where people have the ability to preform such feats it's implied that individuals in that society would have the wisdom to understand the dangers of such an action. Life wouldn't be worth living if it never ended.
theoretically, yes, if they were to encounter a similar spacial anomaly
There was a coast to coast program with Dr Ronald Klatz who talked of being about to live forever. If we could enable cells to continue to replicate. Because aparently our cells have a livespan and the theory is when they give up then our body gives up and grows old.
I know in Star Trek the average human lifespan is 150 years. Also thank goodness this is not today because our economy cannot support such.
Star Trek goes to the well with regenerative youth at least a couple of times, notably in Star Trek: Insurrection. There's no question that if such a "Fountain of Youth" was found in reality, it would be an instant hit. But the true impact of Rascals is the indignity society imposes on children.