What? DOTS is great and extremely performant. CS2 is completely the fault of the developers.
The real issue with Unity is that they don't double down on DOTS + HDRP/URP. I have not opened the editor for a few months but last time I worked in Unity the legacy render pipeline was still the default and documentation around DOTS and HDRP was somewhat lacking which is a shame because when you get it working, it works super well.
DOTS isn't ECS. DOTS was supposed to be, a Data Oriented Tech Stack. Currently it only has ECS with some extra bits. Ergo, DOTS is an unfinished mess. And that unfinished mess --along with a mandate to release for Gamepass-- culminated into CSII suffering from utterly ridiculous issues.
The real issue with Unity is that they don't double down on DOTS + HDRP/URP. I have not opened the editor for a few months but last time I worked in Unity the legacy render pipeline was still the default and documentation around DOTS and HDRP was somewhat lacking which is a shame because when you get it working, it works super well.