> I understand for big companies with millions of users they can't operate in that way but for me risk vs reward is too high.

They absolutely can. If anything, big companies have more resources to build their own cloud based on on-prem or rented bare-metal than smaller companies. It's just all cargo-culting.

The "cloud" is not some kind of unobtanium hardware you absolutely can't get anywhere. With rare exceptions, it's standard hardware you can buy directly from any server & network equipment manufacturer.