Hear me out - tabs are better because there is no possibility of invalid indentation state. "Make invalid states unrepresentable" and all that,

If your style rule is 4 spaces, you have 3 invalid indentation levels for every valid one. Even if you only use two spaces half your possible indentation levels are invalid.

The number of times in my life I've been editing a space-indented file in vim on some sshed server and had to count spaces is way too high.