Swain isn't intended as a support.
Swain isn't intended as a support and was never intended to be one, original Swain wasn't intended to be one and if you look up the rework roadmap it tells you what they were going for.
A Mage Juggernaut/Raidboss that could does and fight in the thick of a fight at close range, and fight against those that were a head with a high cost/high cooldown ult.
At the moment he was "Stomping botlane" A champion that was designed to be a raidboss/mage juggernaut like nasus/darius/ect is a support botlane.
No one see's any issue with this?
That he is mostly viable as a support now? Usually a Iceborn gauntlet tank/on-hit support?
Just because this is working in LCS and he can work well with a team, it DOESN'T MEAN HE IS A GOOD CHAMPION ON HIS OWN and can make plays on his own, like he is intended to be able to.
And like he could before pre-rework, when he actually worked far better towards the end they were going for with this rework.