ES File Explorer has been going downhill for a while ever since it was bought out by a third-party. It's gotten more and more bloated, but the recent addition of a useless charging lock screen with ads was the last straw for many. We've since seen that same junk feature (a version of DU Battery Saver) worm its way into other apps, but at least the developers of ES have wised up and removed it.
The changelog for v18.104.22.168 includes just one item: Removed Charging Boost function for better user experience. For a better user experience, you say? Yes, intrusive adware generally makes for a poor user experience. I can confirm that the charging boost feature is gone in the latest update. It's not in the toolbar and the screen does not pop up when charging.
As for the other apps that were invaded by this junk, they are still affected. In fact, it's expanded to more apps since the last time we talked about it. Google needs to start slashing and burning, but I guess ES gets a pass.