Can someone give me an in-depth explanation why Summoner is arguably the worst DPS?

[Sunako]

garuda's movement will cost u dps u can try messing with it yourself, it just doesn't move and instantly starts casting, it moves and takes its sweet time to turn and face the target especially if it was in a different angle/direction. For example when a target is being on a constant move around the arena and being out the line of sight then yeah it does affect garuda's dps. Also my dear distance matters, also have i forgot the delay of garuda's responsiveness when I use 'place' yeah it's not as smooth "recast time is an open window for adjustment" with every fight, yeah no.

I tried against dummy and you do not lose much dps if you hit wind blade -> move to -> wind blade -> move to. Maybe you lose one or half attack from garuda but it is not end of the world. One attack every min is probably 5~ less dps. Melee dps may lose even more while moving. I hope there would be more that kind of fights where you need move more your pet. Most of fights are like that your garuda sit in the one spot whole fight that make it really boring.