Most of the UI work that actually holds up happens before anyone opens Figma.
If a layout needs a caption to explain what's important, the hierarchy hasn't done its job yet.
Type scale, spacing rhythm, and a small colour palette get decided before any individual screen does. Everything downstream inherits from that.
Once the system exists, individual screens stop being design decisions and start being assembly — which is exactly how it should feel by the tenth screen, not the first.