e.g. -- fossil.
This is exactly the issue with it: its author(s) lament that git has not all of these things integrated, but they are ignoring that this is exactly why fossil cannot gain a wider adoption.
It has opinions about how the team and the project should be run / managed / documented. This is not for the tool dev to have these opinions
There are many different code-review workflows, and for teams that do full-time pair-programming, code review happens in real-time as the code is written.
Trying to bake support for all of that into something that is also a good VCS sounds like a recipe for one of those clock-birdfeeder-machete-flashlight-massager tools that you used to see on the back pages of outdoor magazines in the 90s.