For example, current features in testing are things like funnels, AB/N-Tests, etc. Then extend with any features that allow direct engagement actions for active users.
EDIT: another benefit might be performance of Go over PHP. But that may only show if you plan on hammering the service.
However, Matomo has quite „ok“ server requirements when tracking ~100 million page views per month [1] - and it’s in PHP... Go will most definetly still perform better. And maybe it just felt like it, but I think there‘s just the other week a bunch of tools doing web analytics shown here. So my first thought was „and another?“.
So I hope you‘ll get something of it and you gain some momentun, competition is always good!
[1] https://matomo.org/docs/requirements/#tracking-more-than-100...
The architecture is stream-based analytics instead of query-based.