Based on my experience I would say artwork is by far not as complicated or intensive in workload as the actual simulation of the aircraft, i.e coding, getting the flight model and all of the above right.
Always depends on what level of quality you want to achieve and what aircraft you’re working on.
Do it like Heatblur and 3d scan the whole aircraft. That takes a lot of work for sure.
But by the time the whole aircraft is accurately modeled in detail and working as intended there are already dozens upon dozens of skins available for it.
It’s also more unlikely for artwork to get broken by another DCS update than it is for thousand lines of complex code.
