Agreed, AP Tryndamere is certainly not fun to play against and I don't really see how it can be fun for the person playing it unless they like just slaying minions and split pushing all day. He doesn't deal a particularly large amount of damage, but enough to where it is impossible to duel him because he will just heal any damage he receives and deal enough that you can't regen from it. A 1v1 fight with AP tryndamere lasts a very long time relative to a 1v1 with most any other champion, and there isn't much counterplay (you can try to dodge his E, but the hitbox is pretty obnoxious) for either person involved. I don't think it's as unstoppable as some of the other things in the past have been (I didn't play during release xin era, but if he could literally 1v5 then that would be far worse as there would be literally nothing that the opposing team could do about it), but it's not fun for either side and I'm glad they are nerfing it significantly.