Identity management, role based access control, useful audit logs; all "enterprise" features, probably are very expensive to implement, and make for obvious "up-charge" product segmentation.
I suspect there's some combination of "the community doesn't add useful implementations of these features" and "we can't possibly risk our reputation based on some community contribution" and "we can use this to segment our product to sell to some and give it away to some."
This set of features seems to always get put in the "enterprise, only for licensed / supported customers" and it stinks.... I can understand why, though, and none of these are strictly speaking "security" as much as "compliance"
The original license owner, if a commercial enterprise trying to sell the product alongside the "open" version, has less incentive to accept those features from the community as it would reduce their sales of the enterprise version of the same thing, and may not align with their long-term product roadmap.
In open source, the team managing a codebase isn't under any obligation to accept contributions the community and you are welcome to fork the project, if you like.
Let's say you work at a company that uses Elasticsearch. Let's say you're running a newspaper and you've got your logs in elasticsearch. Let's say one of your reporters ends up getting chopped up while they're visiting the Ostrich embassy to get a marriage license. Now let's say you're then asked "who looked at the logs of the CMS who searched for and found the IP address that was used by that reporter on October 1st 2018"
That example, purely hypothetical, is an example of "security" but not the typical security you'll see in some open source application -- it's an enterprise "compliance" feature that won't be trivial to implement and will be judged not just on completeness but on user interface, ease of use, ease of implementation, etc.
"security" means different things to different people
We did not get certified because we wanted it, we did because the enterprise scale customers forced us to. Due to their internal bureaucracy.
If you want to work with large companies, being SOC certified makes it easier. Part of that is ensuring your vendors are also compliant with good standards and that's best done with SOC reports.
Although few companies have minimum ticket size for enterprise clients and that is a bad thing IMO.
https://news.ycombinator.com/item?id=41304228
This SSO cost post is also interesting: