Your choice of straw man here is interesting. Of the options I mentioned, you seem to have picked only self-purchased hardware with no redundancy and no backup

Your choice of straw man here is interesting. Of the options I mentioned, you seem to have picked only self-purchased hardware with no redundancy and no backups (your addition) to compare with, and also throw in manual deployment (why?). Most businesses are somewhere between a forgotten old dell server in the closet and fully hosted multi-region auto-scaling fully bought in to AWS, and that's OK!