The main cost with on-prem is not the price of the gear but the price of acquiring talent to manage the gear. Most companies simply don't have the skillset internally to properly manage these servers, or even the internal talent to know whether they are hiring a good infrastructure engineer or not during the interview process.
For those that do, your scaling example works against you. If today you can merge three services into one, then why do you need full time infrastructure staff to manage so few servers? And remember, you want 24/7 monitoring, replication for disaster recovery, etc. Most businesses do not have IT infrastructure as a core skill or differentiator, and so they want to farm it out.
For those that do, your scaling example works against you. If today you can merge three services into one, then why do you need full time infrastructure staff to manage so few servers? And remember, you want 24/7 monitoring, replication for disaster recovery, etc. Most businesses do not have IT infrastructure as a core skill or differentiator, and so they want to farm it out.