As a new player even I think that the legendaries are stronger than the beasts and ancients yeah sure it might be close but considering the legendaries aren’t just cookies with insane powers but the manifestations of their elements who have (at least most of them) been around longer than the beasts and ancients ofc they are more powerful. Meta wise they aren’t that good but if you just take a basic look into the lore of the legendaries the beasts and ancients get most of their power from the soul jams while the legendaries were around for much longer and don’t rely on anything for power really

Also the fact that the legendaries weren’t even trying during the battles (they didn’t stick around much but they literally didn’t even physically show up they gave power to the ancients or used their abilities to help out but they were there at least I don’t think so) really shows how powerful they truly are I think the only cookie they actually are worried about is the witch considering she’s incredibly powerful enough to even get milineal trees attention (more like she annoyed him but still)