Because your tech solution is not NOT YOUR business - its one aspect of it, and customized solution may instead of cloud one give you higher efficiency as it is tailored specifically to your needs, plus durability as you totally control it. Cost is totally not important in that regard.
Cost of cloud solution is not comparable to cost of employee - employees build what you want, while on cloud you adapt to the solutions offered and also have to do additional cloud-related duties not relevant to your problem scope (so you payed also for the stuff you don't need).
Cost of cloud solution is not comparable to cost of employee - employees build what you want, while on cloud you adapt to the solutions offered and also have to do additional cloud-related duties not relevant to your problem scope (so you payed also for the stuff you don't need).