His Q is more than just a root. It allows you to dash towards the person that is rooted, which is a lot better than wasting mana/an ability trying to get to them otherwise, especially if you're melee. You can also dash over walls with it.
His W is obvious, provides extra cover for the team.
His E is a shield that damages and slows enemies when it explodes, which could be the difference between getting a kill and losing one. Is also useful when cast on tanks before/as they engage due to the damage and slow.
Daisy is pretty much Tibbers with a knock up. She can also tank/help destroy turrets, which is always a plus.
Also, doesn't his passive still work if he's not jungle? As in, allowing a teammate to pick up the buff after the jungler kills it. Being able to share the jungle buffs with your team seems pretty helpful to me, support or not.
Honestly, there are probably a lot of crazy things you can do with Ivern that I don't know about. I don't like to play him because most don't understand how he works, despite me explaining it several times. I also don't see him played often, as again, I don't think most people know how he works. There are better champions to take as support, but there are also worse ones. There are better Ivern players, but also worse ones. I could understand calling him a troll if he was first timing Ivern support with 0 experience with him, but at least he's actually played him before.
Point is, what are you judging him by? His own personal skills with the champion, or the champion in general?