New DM here about to start a level 3 starfinder campaign. One of my players (Overlord Mystic) claims that "to do anything" You'll need a high dex.

(To put into perspective the party consists of a mechanic, a mystic, a biohacker, an evolutionist, an Operative and a technomancer)

I think this results from a short level one campaign w/ another dm (only lasted 2 sessions) where there was a lot of missing in combat. (At the time me and another player were melee builds while the rest of the party including the now mystic were ranged)

My question is, is the Mystic right? I'm trying to learn as much as I can but they're listing "what everyone says" (which I assume is reddit) is to take a lot into dex. Especially in their case when they take a long arms proficiency and have spells that rely on dex? I'm assuming they're referring to combat but when they start telling other players that dex is something everybody needs to put a lot of points in I get a little concerned, especially when Starfinder seems to be built around both combat and non combat encounters.