So yeah, 100% agree that the "big bulletin approach" is a negative.
I take screenshots of the state of figma at the time we all agreed that "this is it" (or close enough to what we'll implement). Sure I'll leave a link in the epic to the figma "bulletin board" for that feature so that people can find it and look around. But that's it. We're also never gonna implement exactly what's shown in figma (or said screenshots) either because it would take forever to get the designers to actually adjust everything to look like it does in product.
They can never seem to get the look to match what our standard UI library looks like. Which is a shame because every new developer always tries to match what the design shows instead of sticking with the standard library. Honestly, the best thing would be if figma wasn't used at all and the designers just used black and white lines and boxes and focus on good UX instead of pixel perfect UI designs.
Unfortunately that’s been the exception in my personal experience, so most of the time I have to produce pixel-perfect comps that leave nothing to the imagination.
Unfortunately, the product designers don't seem to want to let go of Figma. I understand that this helps them think and organise the layout so perhaps it's not really a problem.
The missing link, often, is then formalizing the design in some form that both developers and designers can use.
At the job I mentioned in my anecdote, we had a guy who lead our design system team. He had string design experience and was also a front end developer. He acted as the interface between the dec Org and the design team to create and develop a component library that was actually used in production and documented on an internal site.
Devs had real code they could use and design could focus on future products and reducing existing things.