Yes, those were abandoned a very long time ago. Mercury materially damages steel alloys. Using it in primers slowly eats your barrel.

its a good thing too, it not very stable, and mercury is not nice.

but its not difficult to manufacture, if we are in the scenario of shortage or absconderance of products.

lead styphnate is common use, but not everyone is happy with lead either. i have a couple boxes of non lead primers, they smell different when they go off but i havnt encountered noticible difference compared to lead primers.