Honestly for those complaining about getting into a plasm party, you have so many options in front of you but refuse to take up those options.
We didn't do well in delve when it first came out with just AF3 armor. Many of the DDs already had REM. And those who didn't dedicated time doing colonization reives and bought adoulin gear. This is truly something you people are overlooking and instead of learning how to overcome your obstacle of getting invited you are here giving us very poor excuses begging to skip a majority of the things we all had to do before having the privilege to enter higher area content.
Here let me give you a small example of why I've been invited to delve.
I have Gear sets for Enhancing, Enfeebling, Fastcast, Refresh, -pdt, mdef, Gravity, Darkmagic, Aumented sky gear such as Dalmatica+1 with Max HQ stats (Fast Cast+6, Magic Accuracy+6, Occ Quickspellcasting +3%), Blood Cuisses (Evasion+7, Fastcast+4, Magic Evasion+4 still a work in progress however use the 12% walk speed for survival), Hayline hat, All relic AF for RDM upgraded to +2, Hvelgamir EMP for Scholar (that way bards do not need to worry about giving me ballads)
Small survival gears that many overlook such as sand mantle (petrification: Physical damage taken -20%) when Pieste NM petrifies, I switch over to -pdt set incase NM attacks lowering damage so that people don't have to waste 150 mp to raise me or wait several minutes of sitting on the side unable to help members due to weakness.
These gear sets put me over 500+ for enfeebling, enhancing, Relic AF+2 with Chainspell extended to +20 seconds, very useful for CS Stun or Raise when party wipes out. Zammzummin staff and Kaikias Cape for landing Gravity, my fast cast is extremely fast allowing me to Spam enfeebling magic quickly. All skills capped, and even so this is only basic gear that I've collected over the past 6 months returning to FFXI a year ago which the other 6 months well spent leveling, skilling, questing and getting missions done. So to say "YOU CAN'T" is just a poor excuse not to get things done.
Adoulin gear gives high INT / Magic Accuracy on the Orvail set so this helped contribute to landing enfeebles. And you can earn plasms off shards solo when you can't find a party to earn it in delve.
It is the reason why the devs said you have many gear options allowing you the ability to defeat Delve areas within 15 minutes, from gear being available through Salvage, NNI, Limbus, Sky, Meebles and several other areas that if you are struggling to win then something is either wrong with your gear, strategy or party setup that you may have to go back and work on these things. Hence why it is end game content made to give everyone an equal opportunity to overcome the creators design and vision.