Primals Unquestionably Bad

[Pentacus]

We only have the Ascian method in lore we don't know that they aren't actively giving out something that has downsides they profit from. It is entirely possible there are "safer" ways to summon.

we actually know of 7 (maybe 8 or 9, it depends how long the ascians have been messing with things and wether tristan's fusion ability counts) summoning methods:

1. the traditional ascian method we all know and love, the "moar crystals! moar worship!" method (from the story, we know this can work on ANYTHING as long as enough people believe in it, it happened with Moggle Mog twelfth of his name (may the smouldering ash I reduced him to never trouble us again), and almost happened with Rhalgr (I honestly doubt that the ascians would be cartoonishly evil to just try and get some kids killed by straight up lying to them, everything they do furthers their plans in some way))
2. the "advanced" method that gave birth to the EX primals (I've not beaten garuda EX yet, but from what Ive been told, it uses some sort of evil thing rather than crystals)
3. Egi summoning, where the summoner focuses on the essence of the primal and not the primal itself (allagan summoning)
4. Tri-disaster, in the quest text, this was actually specifically referred to as "a different way of summoning", possibly using the egi's aether as a spell rather than a traditional summon (also allagan)
5. the "merge with your egi" ability that tristan posessed (what? if the game counts freaking tri-disaster as a summon, I'm sure as hell going to count merging with your egi)
6. loisoix's summoning (interestingly, he seemed to be doing the same thing as the tri-disaster summoning, but with the power of the gods rather than the egis, and their power manifested as a second dalamund-looking structure, so it's possible that what he was doing was also allagan)
7. garuda's summoning of ifrit and titan (interestingly, no crystals were used, instead it required multiple sacrifices of kobolds and amalja, nor was the summoning done by the beast tribes, it was a primal summoning two others)
9.the ascians method of summoning zodiark, although we don't know exactly what it entails
9. it's possible that the beast tribes and allagan empire had a different way of summoning full primals than the one taught by the ascians, at the very least, we can assume that the allagan empire had a method of summoning full primals without requiring worship in order to train their summoners, either that, or the beast tribes must have been summoning the primals VERY frequently to allow enough research to develop egi summoning (I just realized how badass allagan summoners must have been, they needed to fight multiple primals WITHOUT the echo protecting them)

plus, it's implied that the ascians know more summoning methods, they mention in the garuda EX cutscene that they'll "keep giving the beat tribes more and more powerful ways to call upon their gods" (you know, with some new info we learned in 2.1, specifically that ascians can't be seen by people without the echo unless they specifically WANT to be seen, I wonder if the summoner trainer has the echo? she specifically refers to the paragon/ascian that gave tristan belias-egi... which in itself is also interesting)

(there's also the L'Cie summoning that Lightning did, but that's very much unique to herself and is only "summoning" in terms of "thats what it was in XIII")