Earlier quoted context omitted.
Heap was invented for a reason, and some tasks are naturally easier to model with it. The problem is that once it's there, people start using it as the proverbial hammer, and everything looks like a nail even if it isn't. Note though that ""allocate all of memory into a buffer at startup" is a lot more viable if you scope it not to the start of the app, but to the entrypoint of some code that needs to make a complica…
That works for something where the events being handled are like "serve a web page" or "compile a C function". It doesn't work for a spreadsheet or word processor or a web browser.
I'm not convinced it even works very well for either of those cases. It's common in many applications to return the result of a computation as an object in memory, like an array or string of arbitrary length or a treelike structure. Without the ability to allocate memory which exists after a function exits, I'm not sure how you'd do that (short of solutions which create arbitrary limits, like writing to a fixed-size buffer).