It doesn’t. It has a deduping system, which may still leave you with multiple versions installed if there are incompatible version requirements in the dependency tree.
A flat system would mean there’s only ever a single version installed. Or at least, I think that’s what OP means, since that’s the only definition I’ve ever heard.
A flat system would mean there’s only ever a single version installed. Or at least, I think that’s what OP means, since that’s the only definition I’ve ever heard.