Spin off from ✨ Introduce a list of "common cache tags" to reduce lookup query amount Active .
We should add performance test coverage of JSON:API, currently this will need to be FunctionalJavascript testing which isn't technically needed for JSON:API but should work as long as it's for GET requests.
We could also add a FunctionalTest version of PerformanceTestBase using PerformanceTestTrait which skips all the chromedriver-specific logic, this might require a bit of moving things around, but not too much hopefully.
+1 😄
Although I wonder how representative this would be of the real world, where JSON:API performance problems likely only appear on sites with either a huge number of (content) entities or very complex (content) entity types (i.e. with lots of fields on them).