>>1645569For me, it would generally take 4-8 hours for a simple anime screenshot. For more detailed stuff like fanart, it could take anywhere from 5-30+ hours, depending on how complex it is.
I'll give my current project as an example. This is how far I got in this image in 5 hours, starting from scratch. I would say I am about 60% done with the lineart, as I still have to draw a frilly see-through dress and some puffballs. After that I would have to color it, and do some gradient mesh shenanigans that would sink a lot of time. Most likely, it will take me 20 more hours to do that.