Artificial difficulty is when anything detrimental happens regardless of player input.
-Lag
-One Shot mechanics
-Long fights with little to no way to shorten them much
-Enemy invincibility to all counters such as stun,silence,etc
-Unavoidable skills
-Insufficient means by design to tackle obstacles

I would label all you mentioned as "On rails" not as artificial difficulty except for RNG. Because once you learn the rotation of skills and dodging. All content afterwards can be handled the same way not requiring different performance based on specific situations other than gimmicks.