Really? 4K? Mind telling us who those devs are? I'm curious to see that sharpness.
My renders are in 4k, especially for my Match 3 video game,
Factions: Crystals of Control, and then I shrink them as needed. For my Twine stories, they are done the same, but I shrink them even smaller to keep the files smaller. But the detail is always better going from high and then shrinking it down rather than just starting smaller.
My only qualm with these other devs is that they make more money on Patreon than I do, yet I can produce so much content in shorter amounts of time. Hell, Ren'py games like this are even easier than the HTML gigantic things I write, and I finish the entire games within 6 months at a time. Since I actually know what goes into these things, I cannot rationalize the time it takes these others to create- especially making as much money doing it as they do! lol