I personally am not a huge fan of vendor lock in for multiple reasons:

• I've seen cost saving moves to the cloud end up costing a fortune and trapping companies due to over utilization of cloud specific features.
• I've seen S3 failures nearly take down half the internet.
• I've seen companies get stuck in the cloud because they aren't built cloud agnostic.

I choose to use terraform for my cloud provisioning for these reasons:

• It's cloud agnostic so I can use it no matter where I am.
• It isn't difficult to use and uses a relatively easy to read language.
• It tests infrastructure before running it, and enables me to see and keep changes up to date.
• It runs from the same CLI I do most of my CM work from.