I mean people were wiping and dying to normal mode content when this expansion launched, it's just that the fights used for normal mode have looser rules on what constitutes a win or a loss, and gear scaling heavily influences the difficulty as well as how often people do the encounter so the longer people are playing the game, the easier that content gets. Savage mode is a far stricter rule set than normal mode and EX fights use their own set of rules that are distinct from either savage or normal mode.
Savage: Attacks are not televised and only shown through cast bar and some gimmick involving the boss itself, such as a glowing cape or weird crystals. Surviving a mechanic is rare if near impossible for DPS, and surviving a mechanic is equal to taking a death penalty for 30 seconds. If the players cannot clear the content by 10 minutes or roughly that length, they lose the fight. Attacks are allowed to target players but generally are more strict in deployment. The fight is largely a puzzle that has to be understood through failure.
Normal: Attacks are clearly shown via warning markers on the ground. Attacks are allowed to target players and typically do target players to increase variation in attack patterns. Surviving a mechanic is expected, and the punishment for failure is a vulnerability stack. The only way players can die to these encounters is through taking too many vuln stacks or getting knocked off the arena. There is no time limit to complete the fight.
EX Trial: Attacks are clearly televised but only show for brief periods. Attacks are allowed to target players to increase variation, but generally they are more strict in deployment so as to avoid too much variation due to increased damage. Fights involve more pattern and puzzle solving. Failure on mechanics results in a vuln stack, and it is likely that a dps job will die to failing a mechanic without assistance or damage reduction. If the boss is not defeated within 10 minutes or around that number, the fight ends in a loss. The fight is largely a puzzle that has to be understood through failure.
The thing is that they intended EX fights to be the bridge between normal and savage, but as I stated before they raised the skill floor and now EX is just sort of it's own thing floating out there with unreal. Also the way they handle end game as a whole with the savage tier is done poorly as it has no tiers or scaling to accommodate the breadth of different play schedules and times people have who engage in it. The content shouldn't take someone more than two months to clear but unfortunately it ends up doing just that since many people can't dedicate a four to five night a week raid schedule with the same folks, and bless those that do because without them the vast majority of people doing savage likely couldn't even complete the content.