Well... kinda. I'd say this is the result of a mismatch between "refresh everything, anything could have changed" and what most people actually want when refre

Well... kinda. I'd say this is the result of a mismatch between "refresh everything, anything could have changed" and what most people actually want when refreshing, which is "check for new content". "cache-control: immutable" at least lets servers declare a contract that pushes those two closer towards each other, and it also works perfectly for those cache-busting resource-version-params, which browsers haven't been able to trust. Which is probably why Chrome had that POST-invalidation thing - there are a lot of flawed cache headers out there, and users don't care that you're following the spec when things break.