The spaces versus tabs debate can look trivial from the outside. In practice, though, it touches very real concerns: readability, consistency, editor ergonomics, and team discipline. Under a formatting detail, there is often a broader conversation about how a team wants to work.
The argument for spaces
Spaces create a more predictable visual result across editors and environments. A file indented with spaces tends to look the same wherever it is opened. That consistency is reassuring in collaborative codebases.
It also matches many official style guides, which recommend a precise number of spaces per indentation level.
The argument for tabs
Tabs give more flexibility to the individual developer. Their visual width can be changed per editor without modifying the file itself.
For some people, this better matches the original meaning of indentation: a tab is meant to represent a level, while multiple spaces use a generic character for a structural role.
The real issue is consistency
In the end, the best answer is rarely universal. What matters most is avoiding arbitrary mixtures and agreeing on a stable convention inside the project.
Modern tooling also makes the debate less dramatic. Formatters, linters, and editors can enforce consistency without turning every pull request into a cultural war.
Conclusion
Spaces or tabs is less about winning a permanent argument and more about choosing the option that creates the least friction for the team. Consistency usually matters more than preference.