Well, the root cause why the plugin ecosystem is a mess is the way plugins management and monetization is implemented in the vanilla wp.
As oposed to, e.g. Atlassian Jira plugins, WP doesn't really help plugin developers to seamlessly integrate with the core product.
Plugin devs can generally NOT be trusted with seamlessly integrating their plugins because it usually leads to all kinds of dark patterns and poor UI for WP as a whole. WP.org's strict plugin guidelines is one of the main reasons why plugins behave relatively well considering how huge the WP.org repository is.