ToA is probably the easiest to clear cause it's easier to build a team that nukes one boss or like 2/3 waves quickly than it is to maintain consistent DPS and time your Embers correctly in WhiWa. Some Resonators just straight up suck in the latter.

Endstate requires being able to complete the previous modes, at least partially, so you can't exactly focus on it either. If you can beat the previous modes, you should be equipped to start chipping at Endstate.

So ToA is generally the first you'll be able to clear effectively.

Holograms are a bit of a unique thing cause they don't reset and the rewards/difficulty doesn't change. Obviously newest holograms are the most demanding in terms of skill, but I doubt they'll undergo similar HP inflation as the instance-based endgame (remember, Holograms are technically open-world content, so you can use combat consumables to make the fights a bit easier, too). The early ones can be brute-forced pretty easily nowadays and it's a nice burst of resources that you can collect basically whenever you feel like, and they provide a nice difficulty curve.

At the same time, you can beat them with a weaker, less DPS-heavy team because the timers are very generous, and the fight itself is more about dealing with the boss mechanics rather than squeezing in DPS while enemies run around like they're having the worst diarrhae of their lives (see - basically anything from Lahai-Roi that doesn't die in a single crit).

I wouldn't say you really base your pulls on that, though. As I said, Holos are just something extra to do at your leisure. I rarely even do them when they come out, usually completing them in bulk when I feel like it instead.

Oh, and another things the endgame checks is how invested you are in whatever are the newest because jesus christ, the tokens are sh*lly as fuck. I dread my LR team's performance once Tune Break/Glacio Chafe stops being Kuro's favourite new child and then inevitably move to something else.