Yeah, because rendering doesn't take time at all, right?
Gods...
The amount of time needed is not the issue. Does rendering require you to be in front of the computer all the time it takes? Forgive my assumptions, and trust me,
I'm not taking away any merit from any dev using 3DCG in ANY way, since they need to select models, to apply or make the poses by themselves and also compose every scene. And that takes time AND effort AND creativity. These games also need the scripting and the coding. But correct me if I'm wrong, cannot a 3D artist queue renders and then, IDK, go to work, do house chores, etc, etc? Well, 2D artists can't. They also usually create from scratch. Sketch, linework, color, shades... You need me to keep going?
Again, most solo devs, even those using 3D renders tends to bring small updates when they update monthly. A lot of them bring small updates once every two months. There are a few notable exceptions, but hey, everyone has a life, has to earn a living and so on. This is especially true when it comes to 2D artists. You know, good 2D art require hours, and months, and years of practice. That usually means you probably are working as an illustrator at some level, either professionally or maybe doing some occasional amateurish commisions. Either way you are dividing your time between what gives you an (usually small) income and a game in which you need to work for free for months before donations could actually help you to barely scrape by.
Just my point of view. In any case, given that the pace doesn't feel enough for you, have you considered perhaps to offer your help to the dev? Maybe you can draw additional art, help them with colouring, with coding or... good feedback and moral support? How about that?