Why Learn CloudFormation?
Since you're here, you probably know what CloudFormation is. If you don't, here it is in a nutshell: write up everything you want AWS to build, upload it to CloudFormation, and ... that's it. AWS takes care of the rest and you're good to go.
But why should you learn it? Why, given the short hours of the day, is it worth picking up this tool? Because it will save you massive amounts of time and cost that would other wise go towards the old way of doing things. Manually configuring resources. Creating custom scripts with very little portability or reusability. Or if you're architecture is based in a traditional data center, dealing with that entire universe of patching, managing, and configuring.
On the other hand, with CloudFormation, you can do it all using nothing but code. This means that you can use all of the tools and resources out there to deal with code like version control, ease of collaboration, accurate review processes, and more. Disaster recovery becomes the code you've written. History of your infrastructure is easily documented. Changes to components are clear and obvious.
In 2 to 5 years infrastructure as code will be synonymous with DevOps and essential to tech companies. To an extent this is already the case since things like Ansible, Puppet, and Chef are core to configurations. However, in the future, both configuration AND provisioning of infrastructure will be the path forward.
Since AWS seems to just keep growing and going? CloudFormation is the perfect choice if you want a skill set that's stable, battle tested, and sure to be around for years.