Content should be challenging to execute... Not challenging to learn

[MisterLucie]

sure i could memorize a string of 50 different mechanics, but that doesn't say anything about my actual proficiency at my job.

Again, difficulty in an encounter stems from being proficient at your job while also executing numerous mechanics properly. You can dodge every mechanic in the world and still be useless if you aren't doing enough dps. It's not a one or the other deal.