This is a good plugin, it should be used on your own site. WordPress undeniably memory hogging and waste of space when it comes to media or even database if you will. But the overall eco-system just don’t allow you to play with whatever default WordPress has, such as media sizes or even the cronjob. Unless it’s your own site and you know what you’re doing.
Yes, in short, WordPress are getting more and more complex and complicated for beginner. No, Gutenberg editor is not helping yet.