Just pretend that magically everybody knew how to code. Wouldn't designs just be done in the browser? No longer do you have to maintain these design artifacts post handover. There would be no unrealistic designs that do not consider the constraints of a browser window.
I know this is unrealistic but I often think about this.
Most places use consistent patterns for padding, space, etc. But a lot of things need adjusted visually for polish. Tweaking things in devtools is fine for quick things, but can be lost on browser refresh.
Tools like "CSS Pro" make it easier. Saving devtools state makes it easier. But neither quite compare with hitting the arrow keys a few times to see what small adjustments look like. Or dragging a card to a different spot. Or duplicating a component three times with slight variations to see them side-by-side.
I'm a developer that uses Figma occasionally. It's just less frustrating to get the "look" down before jumping into code.