Having antigravity is useful because Gemini 3.1 is pretty good at generating UI sugar. Claude 4.6 Opus provides nothing to write home about. Their shadcn looksmaxxing hasn't generalized to writing good desktop UIs.
Raycast's only edge here seems to be the fact that they are obviously very good at Mac app development and probably have impeccable skills/documentation for building them.
Taking a step back, it's pretty clear that Raycast is angling for an Apple acquisition here with this play. If I'm Apple, the reason to buy a product/team like this is a no-brainer.