I don't think it is. There are many many cases where you do want to own them. The people you rent yours from are making a shit load of money so it doesn't sound that bad of an idea
I buy lots of things from people who make a pile of money from low margin goods/services sheerly on scale. There are many things i could not reproduce more cheaply from constituent parts, even if i value my time at $0.
This includes things I have expertise in.
you're going to save money by having your own physical servers?