This is a tracking task for the general work of moving alerts from Icinga to Prometheus/Alertmanager.
Note that the title says most because while the perfect end goal is to migrate all alerts (and thus shut down Icinga) that might be unpractical and/or too much effort with respect to the gains.
On a pragmatic level though what we can do is reduce Icinga' scope over time, and turn it into a "backend" component. In this scenario for example we would stop using Icinga's web UI for all/most operations, and delegate all functionality to AM / alerts.w.o