The best point to play Final Fantasy XIV is at the start of a new expansion. After the expansion drops, every subsequent patch increases the item level slightly to give a sense of progress and as a consequence, the older content becomes easier. The reason this is done is so that people can more easily catch up to the max level crowd and participate in the same activities, because more often then not the MSQ locks content behind it, and some side routes also have pre-requisite runs like the current 24 man raids.

The worst point in the entire cycle is the "final breath" of the current expansion because no matter how the statistics are scaled, the content released at the start of the expansion is practically 5 levels behind the current characters. To give an example of this, look at the endwalker dungeons and look at the item levels on the gear that the dungeons are dropping: In most cases the poetics gear lasts up to whatever the mid level is, and then is overtaken by dungeon gear shortly after. Character level has little impact on the capabilities of damage outside of whatever multipliers are gained from new abilities or just modded old abilities, so for all intents and purposes people with 660 iLvL are level 95.

Additionally, this expansion is sort of turning into the wild west with content because the stat squish changed a lot of factors. I went back to my old recordings of e12s when it was current and compared them to p12s now, and the scaling of damage vs peoples HP and defense is just completely trash in endwalker. Gear could help carry people through e12s by allowing them to survive hits that would otherwise kill them which prevented the issues we see currently in late end game, where as in this current expansion all the attacks that are designed to do a high amount of damage usually are going to be lethal unless someone remembers to throw a mitigation up, and the only time it isn't is when people are at 100% hp. Even in that later case, healers are being worked a lot harder to keep people up if they get that low. (also RIP ranged since they drew the short straw for some reason. They just die way more often from failed mits than anyone else)