I’ve been working with network monitoring tools for a long time. Working with network devices, there is still today a very high probability you have to deal with SNMP. If you work with modern applications or infrastructure, especially in dynamic environments with containers, you will inevitably run into Prometheus and its ecosystem when you need to design and build monitoring solutions.
By design, both agents have different goals in mind. The world was very different when SNMP aimed to be “simple” in 1980 as it was for Prometheus in 2012.