Auto entities is honestly probably my most common card. I use it everywhere since I’m always trying to avoid hard coding lists of entity IDs everywhere in HA. I also feel like its very heavily used based on how often I see it name dropped or in shared configs around this forum.
Core has entity filter I guess but really that’s barely better then the entities card since you still have to list out every entity. And can’t wrap other cards with it like you can with auto entities. It would be nice to see auto entities or something along those lines make it’s way into core.
It actually was originally part of Core, when Lovelace was in development/beta. And had been removed (after which it became “Monstercard”, which eventually lead to the auto entities).
I’m using this a lot as well. Because of the great filters you can set. For example the “groups”. I’ve motion groups and contact sensor groups. All together you can only show the state, but can’t see which individual sensor is the one causing the state. Here is the auto entities very helpful to create a glance card with only the group entities.
(The whole individual group entities is another wth topic)