Professional game teams use visual tools. Visual tools allow non-programmers to do work / prep files / iterate on ideas / create animations without an engineer

Professional game teams use visual tools. Visual tools allow non-programmers to do work / prep files / iterate on ideas / create animations without an engineer being involved. An individual indie dev doesn't care about that, so having hardcoded data may be a faster workflow. In the studios I've worked UI artists work on the UI files and then pass them off to engineers to connect to the code. Tuning data comes from spreadsheets, and art/animation comes from artists, and they generally have a one-button import process that doesn't involve an engineer.