They use a laser to melt the top layer of a bed of metal powder, lower the bed, spread more powder, repeat. It results in a generally more porus part than cast or forged material, thus weaker, but can make otherwise impossible to manufacture geometries that can be lighter weight, which can reduce the strength requirements as well. A jesus nut is not an application you skimp on strength lol

F1 teams 3D print (laser metal sintering more specifically) their pistons these days, so I'd say at the bleeding edge of the tech you can create pretty strong parts. But indeed, anything which a consumer is likely going to be able to afford won't be nearly as strong.