I’ve seen this repeatedly over my career. At the large organizations I’ve worked at (.edu, .gov), unless you have a large general tools budget it’s surprisingly hard to beat the open-source tools - simply running a procurement takes months and might require arguments with non-technical staff who don’t understand why certain options are not truly equivalent even if the salesperson swears they are. This is how you end up spending 7+ figures on enterprise tools while the technical staff are all using Prometheus, Grafana, and ELK because they actually work and are available to the entire group.
On the “clearly crazy to invest in building your own” front I think it’s useful to add the nuance about how much of that time is purely related to the product and how much is the tuning, integration, understanding the data, etc. which every product requires. I think we’re prone to underestimate the latter and have something like Splunk save less time and cost more than expected because the commodity part it optimized for wasn’t as much of the whole as anticipated.
On the “clearly crazy to invest in building your own” front I think it’s useful to add the nuance about how much of that time is purely related to the product and how much is the tuning, integration, understanding the data, etc. which every product requires. I think we’re prone to underestimate the latter and have something like Splunk save less time and cost more than expected because the commodity part it optimized for wasn’t as much of the whole as anticipated.