we don’t have a classical devops setup where we build something and have one production environment - we’re running software in various setups (ranging from SaaS (with multiple production environments (for legal reasons)) to on-prem - with more than 100 production environments, most of which are not managed by us), in various different versions (you won’t get an on-prem customer to upgrade every 5min even if you’d release that often 
) and various setups (not every customer has the same set of features and thus not the same set of applications) and various different configurations. furthermore, our software product offering is quite vast (we’re not just talking about 10-20 microservices here).
e.g. we have / will potentially have multiple opensearch clusters running in the same k8s namespace, depending on the use-cases - but they should of course still share most config-related things (i.e. i don’t want to build up the k8s resources manually for each of them - i just want the name to be different).
helm charts were not offering this capability when we started on this journey with k8s (quite a while ago) - they might be now (to be honest i’m not sure, haven’t looked at them in detail) but we’re quite heavily invested in our current approach. so while we might switch at some point i’d probably even then still not be able to use standard opensearch helm charts.