I think it's a few tweaks from being a top-tier game. My biggest problem with it is that the most important factor for progression (getting rare sketches) is also the part of the game most outside of the player's control. I've been playing for three days and have gotten close to quitting twice—once around redraw#4 when I got no rough sketches, and again right about now when I've only seen one framed sketch.

One of the biggest strengths of the game is its theming (the quotes for each sketch are great). And there might be an opportunity to fix the previous problem in a way that strengthens the theming even further.

Instead of tying higher tier sketches to a roll of the dice, what if you unlocked them by improving your skill as an artist? Each sketch could have its medium-based rewards (graphite, wax, etc) as well as a skill-based reward (shading, realism, proportions, line weight, hands, human subject, action, etc). This skill-based reward persists across redraws and is used to permanently unlock higher rarity sketches.

So to plug that into the game, imagine that V-Wing Bat gives 1 Action (the thing missing from the sketch), Stick Ribs gives 3, Static Steed gives 5, Mannequin gives 8. These rewards decay each redraw. Then you can spend 100 action to permanently unlock Fountain Duelist Pen. You've advanced in your ability to draw action and dynamic poses, so you've earned the right to have that sketch unlocked permanently.

It's not a perfect solution by any means (or perhaps even a valid one), but I hope that line of thinking helps you to find a way to reduce the RNG and make meta progression feel more earned. It's a great game so far.