How many spells do Summoner even have?

[VictorSpoils]

To put it simply, its because their 'peak rotation' is linear & very foolproof.

Can't Aethercharge/Summon Bahamut? "Oh, I need to have carby out... "
Can't use Legos? "Oh, I need to finish Aethercharge/Summon Bahamut phase first..."
Can't use Gemshine/Precious Brilliance & Astral Flow? "Oh I need to use Bahamut/Phoenix/Legos..."
Can't use Ruin IV & Festers? "Oh I need to use Energy Drain/Siphon..."
Ruin IV is timed exactly the same as its catalyst? "Oh so I need to expend it before using another..."
Then you realize there's an insane amount of potency shoehorned into Bahamut's phase? "Oh hmm Bahamy is yum yum op! Let's buff it with Searing Light!"

What else? Maybe super dumping 4 Festers into raidbuff window? Maybe learning where in the fight it's safe to standstill to cast during Ifrit phase (something that all spellcasters will naturally learn)? Maybe learning where in the fight it's safe enough to not murder yourself or your partymate with Crimson Cyclone? Maybe learning whether it's worthy to Swift a Slipstream cast to catch raidbuff window in a raidbuff heavy compo groups? Maybe saving it for Ruby Rites casts or combat raise? Not that SMN is lacking in instants at this point. They're memed for being a phys ranged dps in caster coat not without a reason.

It's hard to fail playing a SMN because the restriction it implore to player restrict player from failing for the most part.

The best part is when you see two or more SMNs and they nonchalantly use Searing Light at the same time. Can't really blame them for not caring.

I thought I read somewhere last year that using it on Ifrit was a slight DPS gain over using it on Garuda so I’ve just been doing that. Some Discord DPS calculating person probably figured it’s a 3 DPS increase or something.

I just like knowing I will never have more than 1 hard cast per summon so I feel like I have more mobility.

That was probably before they changed the Ruby recast time from 2.5s to 3s (cast time is 2.8s). Now it's either for movement, getting the Garuda DoT out quicker, getting one last hit in, or maybe a Raise in a tense situation.