You don't really know how omc works so you. Apm definitely adds value to the organisations.
Ever heard of new relic, wavefront. You can either waste your time debugging where the delay is coming from, which call is taking more time. Or even do brute force way of finding the culprit call. But that does not dilute the feature set provided by Apm products.
Oracle Apm is a challenger. Nevertheless, each product needs to keep innovating and provide value for money.
The main disadvantage for oracle cloud is the isolation between various services. Rather than providing one shop for everything, there are several shops within oracle, selling services which are best sold at Samee point of sale to give customer ease of purchase and use.