You mean a string of nerfs, idk about you but I used to love eating teammates and using the speed buff to chase enemies, riot took that away because sometimes it would speed him up when he wasn't really running towards an enemy champion.
Which makes it seem a lot more like they just needed to reduce the cone angle for when it would check if he was facing an enemy or not.
They also made it so allies cant click his R in combat so he doesn't use it as a second devour....but now I cant use it to catch enemies who are running away, me and a teammate will just sit there stupidly waiting for them to be out of combat.
Now tahm`s ult is only good for rotating defensively to protect towers since he has no innate waveclear or way to quickly damage turrets ( his passive doesn't stack on minions and turrets)
TBH they should have just made him back into a scaling champion so he doesn't lanebully so hard, his kit is literally designed for a weak champion that just wants to buy time but now that the damage is there for free so its just incredibly oppressive.