Riot's moving League downhill.
Not because they changed ADCs or anything, no its a single nerf they went through with.
Riot nerfed the tenacity on merc treads while lowering the cost. There are several problems with this.
A) CC in conjunction with mobility has already been getting to a breaking point vs many melee. Its essentially the cause of the bruiser reworks. CC was still potent even against merc tread users, barring Mundo and Irelia so why the nerf?
B) The reason for the nerf is likely riot trying to inject more 'choices' as far as boots go. However, with how insanely abundant low CD CC is in this game, merc treads weren't popular because it was powerful, it was popular because it was required. There are plenty of games where other options are taken, and it was because of their niche use. Look at mages, Ionian or Sorc. Why is it a problem that bruisers/tanks go Tabi/Merc almost exclusively? You actually limited choice, making Merc function effectively only for tanks now. Its Tabi all the way for bruisers with the new MR item buffs.
C)Buying Merc feels terrible now. The 20% isn't noticable. The only thing I find myself wanting merc treads for is the MR, since I know the tenacity won't be enough to stop me from getting bursted during pretty much any CC unless I'm full tank.
D) The very worst part is the complete and utter lack of context on the change. It doesn't feel like there was any logic following the change, and if its a problem, its very likely Riot will not follow through with correcting it now.
P.S. Also, I hope you guys have a good rework planned for Ryze, since he barely functions in games he isn't insanely snowballed now.