I feel like Minecraft should be the exception to nearly every single rule in game dev (except when it itself is the rule). That said, there's a difference betw

I feel like Minecraft should be the exception to nearly every single rule in game dev (except when it itself is the rule). That said, there's a difference between making an engine for a game like Minecraft vs. the kind of engine needed for Limit Theory. At the end of the day, it's the same stories and questions about core competency present in almost every business. If you want to build a shelf, and you have to start by making the tools that will cut the tree that will become the shelf... it's going to be a while until you see a shelf, and in the process you'll probably be producing more useful tools than shelves. Unity is popular for the same reasons AWS is popular: It allows you to focus your time on what you excel at, instead of spending it reinventing various wheels. Some businesses (and games) can succeed despite reinventing those wheels, not necessarily because of it. And in some extremely rare cases, "what you excel at" is both building the engine and making an excellent game out of it (Present company included; I'd recognize your name anywhere). Stardew Valley and The Witness are the only two examples I can give off-hand of significant, outstanding, indie games that were released with a custom engine. And I would maintain that in both cases, it wasn't necessary to create the engine. In SDV's case it's even questionable if it actually helped at all. Every other example I could come up predates the days of high quality engines being readily available to sub-$100k budget games. Edit: I'll add Psychonauts to that list; once again, a decision of questionable gain that the author AIUI regretted.