GitHub provides great user experience ans most developers are familiar with it. There is also an attractive pricing model for those who already have a Visual Studio subscription.
We also don't like the "everything in one tool" approach from GitHub as there are better tools for build system, package registries, etc. on the market.
Terraform provides a cloud-provider agnostic way of provisioning cloud infrastructure while AWS CloudFormation is limited to AWS.
Pulumi is a great tool that provides similar features as Terraform, including advanced features like policy and cost management.
We see that Terraform has great support in the cloud community. For most cloud services we use, there is an official Terraform provider. We also believe in the declarative model of HCL, which is why we chose Terraform over Pulumi. However, we still keep an eye on Pulumi's progress.
Ansible is great for provisioning software and configuration within virtual machines, but we don't think that Ansible is the right tool for provisioning cloud infrastructure since it's built around the assumption that there is an inventory of remote machines. Terraform also supports more services that we use than Ansible.
1Password provides excellent security features, combined with a great user experience. All data is stored in the European Union (on 1password.eu).
Since we provision our infrastructure as code via Terraform, we were also looking for a tool that brings an official Terraform provider, which is the case for 1Password. We use this to administer vaults and to access sensitive information from within Terraform runs.
1Password provides zero-knowledge encryption, multi-factor authentication, audit logs, client enforcement and user provisioning and de-provisioning via SCIM.
You can easily synchronise credentials across all supported devices and you get password management integration for all major browsers including those for mobile devices.