Realistically, it shouldn't matter what you choose, git, TFS, SVN, etc. SFDX's "create new project" command assumes a git format as the default, so you will need to delete some folders and files (.git and .gitignore for starters), and create the TFS equivalents (e.g. a .tfignore file). Aside from the extra setup, the differences come down to things like "do your tools support TFS?" and "do you even have a TFS server?".
Some people like one technology over another, but as long as it gets the job done the way you want, it doesn't matter which you use. SFDX tools deal primarily with pushing/pulling metadata, creating packages, etc, all of which are CVS (Code Versioning System) agnostic. Salesforce even encourages you to choose whichever tools you want to use, which is why it's a CLI to begin with.
Any IDE can can use CLI tools can use SFDX, and any repository that can store files can work with the DX format. Yes, there's tooling built for VS Code and git by default, but that's to give developers a "path of least resistance" so they can just install and go in minutes. Developers are free to choose whichever CVS and IDE/Tools work for them.