I don't know about YOU, but I'd be too tired by that time to paint. Then, on top of that, you'd spend hours and hours cross-hatching tiny linear strokes of paint in building up just the right tones and textures to color your carefully drawn images on wood panels you'd sawed, hewn, and planed the day before. And that doesn't count applying the layer upon layer of finely ground plaster mixed with rabbit skin glue (which your neighbors hate the smell of as you boil down all those rancid pelts). And of course you could only paint during the daylight hours, not that you could stay awake very long into the night after all that anyway.
Well, the Flemish artist, Jan Van Eyck, had those problems, at least up until about 1500. No doubt he wasn't the FIRST artist to say to himself, "There's GOT to be an easier way to make a living." Except that he did something about it. Egg tempera, while rich in color, was poor in subtlety, even in expert hands. So, he invented oil painting. Blending his same hard-earned pigments into linseed oil allowed him HOURS, even DAYS to work and rework a given area, instead of mere minutes. And oils were especially well-suited for painting on those new, light, sturdy, gessoed LINEN stretched canvases, rather than those heavy, awkward old boards. Moreover, they gave him a practically UNLIMITED scope of space upon which to craft his masterpieces. Now if only he could round up a few more appentices to scrounge and grind pigments, life would be a still life bowl full of cherries.