For our specific case it's actually pretty good, we've built a lot of discipline around maintainability, but in general this is a recurring problem in tech teams who might not be able to afford the time it takes to gain discipline.
> What is the alternative to this tool that lowers the cognitive barrier / builds the right muscles for the team to understand what they should / shouldnt depend on?
Some programming languages allow you to split the codebase into modular units (npm workspaces, cargo workspaces, etc..) which forces developers to modularize things, and dependencies between modules need to be explicitly declared.
This is good, but usually not enough, as nothing prevents you to mess things up within a module/workspace.
There's some other tooling with similar functionality to dep-tree, but language-specific and with visualizations not suitable for large codebases (.dot files, 2d svgs...)