* "Actions" are basically only useful to me as an active project contributor.
* "Security" is a pretty niche tab -- I think personally I've clicked on it only a handful of times, ever
* "Insights" I had forgotten about to be honest (and obviously don't use it), but even as I look at it now, I think it's somewhat useful for judging how active a project. For mature projects (that don't need active development) it says almost nothing. I personally do a fuzzy judgement on Releases, popularity, # Issues open/closed, # merged PRs, # and age of open PRs, # contributors.
I use "Releases" as a consumer in mainly three ways:
1) To help judge the quality and maturity of a project, in terms of how easy it will be to deal with as a dependency. Are releases being used (vs published adhoc)? Are there betas? Is there a changelog or curated release notes? Is semantic versioning being used? How frequent are releases?
2) When updating dependencies, and looking for breaking changes or things I need to update in usage.
3) For downloading, when it's the only way -- though this is typically linked from the main README, and I'd generally only care about the latest.