You can do that with homebrew too. But in the case of Terraform, where you can have developers on Windows and macOS and CI/CD pipeines based on Debian/Ubuntu/CentOS/Alpine/etc, it's handy having everyone use the same tool for managing Terraform versions.
It's just like how you wouldn't have different people manage the same Python codebase with different package managers. You agree on the standard for that business or project and have every instantiation of that project follow that same standard.
I definitely agree overall. My last job was standardized on Homebrew and used tfswitch; I personally translated to MacPorts but I do agree that tying a project to a specific package manager (and thus OS, etc.) isn’t advisable.
It's just like how you wouldn't have different people manage the same Python codebase with different package managers. You agree on the standard for that business or project and have every instantiation of that project follow that same standard.