I am well aware of that 8 MiB rlimit. It's just a default that root can change. It's both too much and not enough.

It's too much because even 8 MiB is excessive without overcommit.

It's not enough because nothing about the ELF binary even bothers to claim that any particular amount of stack is enough.

I really wouldn't call "8 MiB" an answer to how much stack space should be allocated or committed.