Thought for 12s
Implementing globally standardized tokens allows for a truly unified chat experience across all of Stripe's products.
This will save time and effort by removing the need to create unique instances of components per surface.
At the same time this adds flexibility as both designers and developers will be familiar with the core design language across surfaces.
Thought for 2s
Mostly, because I heard Inter might be used in Dashboard 😂. Adding another custom font into the mix will only make fragmentation and portability worse.
As a designer who frequently works across surfaces, I've seen how much time and effort is wasted by having to create unique instances of components per surface.
Since Helm is the newest design system, building upon it seems to be sensible.