Judging by https://github.com/hashicorp/vagrant/issues/7263, I would say that they are the "GNOME" of devops tooling. The quickstart is great, and you feel empowered when your use cases are supported. Beyond that, good luck.
> They are the de-facto standard in DevOps tooling
Im in cloud automation 8+ years. No they are not de-facto standard. For AWS projects, I much prefer Cloudformation. App devs use venv or similar, not Vagrant.
I’d use their CI/CD if they had one, like GitLab, but looks like they don’t?
I've used terraform in 50% of my jobs over recent years.
But even in the companies where I've used AWS and cloudformation we still use Hashicorp tooling. For example we use cloudformation at the current company to handle our AWS infrastructure, but the AMIs launched are generated with packer.
I could probably find more, but many (most?) large tech companies use one or more of the Hashicorp suite. I don't think it's unfair to say that they are the standard toolset for certain roles.