The thing is that most of it is workable, and the stuff that isn't is stuff you can probably get help for. Most of the T1s in Zi'tah are soloable, and many of those pieces still have many uses, so if you're having a hard time it shouldn't be too bad to get others to assist you. I still use 4/5 Naga for various uses, 3/5 Rawhide, 5/5 Pursuer's (albeit on my same-account mule since I don't play ranged jobs on my main), 2/5 Despair, etc. Short of someone having every single piece, there's still a reason to go back.

Once you hit T2s, yeah, that's where you start to hit the wall, and it's annoyance I myself am working to surmount, because otherwise I'm forced to rely on LSmates to pop t3s for me to fight (ofc I still need help with fighting t3s so that's okay). Nibiru weapons are generally still good, particularly the sword and club for BLUs because the former has a nice chunk of accuracy on Path... B, I think and the latter is one of their better nuke tools. The other Nibiru items are so-so from a glance, but still a step up and likely something these other people who have not progressed would like. T3s you're going to need a party for and knowledge of each NM, but you're going to find that T3s are still fairly relevant content.

When you get to Ru'Aun, it's much the same. About half of the T1s are easily soloable; the Caturae suck because some have doom gaze and your tank trusts just aren't smart enough to turn away. Atop that, even if you tank and turn away, your DD trusts just don't do enough damage. This is unfortunately where you hit another wall, but there are still people who want the abjurations, so it's still doable. It's always worth shouting, if nothing else to get a tank or DD to pair with you and you can fill the rest with support Trusts. T2/3 Ru'Aun is always in demand between weapons and abjurations, and the fact that the fights are tricky to solo. I've done Naphula solo a few times, and I've gotten Hanbi down to 5%ish more than once, but that's all I've been able to do and I'm moderately well geared.

And once you've gotten to Reisenjima, you're up to modern content. At this point you should have some decent accuracy gear between Abjuration pieces and Zi'tah armor, not to mention accessories. An example of an acc set for... let's just use MNK for now. Gonna make some assumptions on gear you should have by this point:

Nibiru Santi Path A (+25 Acc) | Empty | Empty | Honed Tathlum (+15 Acc)
Whirlpool Mask (+25 Acc) | Ej Necklace (+15 Acc) | Steelflash Earring (+8 Acc) | Bladeborn Earring
Rawhide Vest (+15 Acc)* | Rawhide Gloves (+20 Acc, tons of DEX)* | Patricius Ring (+8 Acc) | Enlivened Ring (+6 Acc, may have name wrong, DEX sparks ring)
Anchoret's Mantle (+20 Acc base) | Anguinus Belt (+15 Acc) | Bhikku Hose (+13 Acc) | Rawhide Boots (+18 Acc)*

Note that all of your Rawhide pieces can be augmented with HP+50/Acc+15/Evasion+20 on Path B, so that's an additional +45 Acc you can get on that set above, for a grand total of +248 Accuracy in that gear. With capped h2h skill and Sublime Sushi, you should be hitting things modestly well. Again, this is your post-Zi'tah setup, and you will need to think carefully through the NMs for the Rawhide pieces: Cunnast for boots, Gestalt for hands (watch those Dread Spikes, bring a Dispel trust), and Vidala for body, the last of which you'll need help on.