Figma made a mistake including the absolute positioning in their Dev mode. It's never useful, and leads to confused engineers like this.
Figma is a design tool. It is used by designers as a way to build the visual mocks of software. It's not building HTML under the hood. As a frontend engineer, I have to interpret the designs given to me and translate the layouts into something that will be responsive, cope with different data, etc. that part is the job of a frontend engineer, and so far there is no tooling that solves that.
The Figma dev mode helps shortcut some of that work, by providing easy copy-paste for attributes like background, border, fonts, spacing etc. it's a timesaver. But you should never copy the whole thing.
Figma is a design tool. It is used by designers as a way to build the visual mocks of software. It's not building HTML under the hood. As a frontend engineer, I have to interpret the designs given to me and translate the layouts into something that will be responsive, cope with different data, etc. that part is the job of a frontend engineer, and so far there is no tooling that solves that.
The Figma dev mode helps shortcut some of that work, by providing easy copy-paste for attributes like background, border, fonts, spacing etc. it's a timesaver. But you should never copy the whole thing.