The flip side to that argument is that life has a lot of cheap creatures (and Mitosis) that will make this card more useful there than in other elements and that perhaps it should be costed accordingly.
I think the cost is where should be, despite that - most elements have a 2-3 cost card focused on taking out creatures in one shot. Since Roar is reliant on a player constantly playing creatures, it falls on the weaker side of the CC spectrum (not that unlike Freeze, it will not negate abilities either.) In any element, I'd argue this should actually cost 1
| 1
- but since this is Life, having CC be slightly less efficient here seems reasonable.