As long as there is no explicit solution to notifications in WP, the developers will use whatever serves their needs. And you can't blame them! Being able to market a product is an important part of making pretty much any work in the WP ecosystem sustainable. Telling devs they are doing it wrong when there currently is no way of doing it right is not really moving things forward.

Anyone who is willing to help on solving this (very impactful) problem with WP should look into the WP Notify feature project: https://make.wordpress.org/core/2019/08/05/feature-project-proposal-wp-notify/

Its main goal is to provide explicit ways for devs to provide notifications and for users to decide how and when to receive them.