I keep seeing this claim make its rounds. "AD items are buffed." No, they're not. They're rebalanced. Most of them give less AD. Less attack speed. More crit. A variety of life steal/spellvamp options, but no feasible way to stack them without sacrificing too much in other areas. Choices between flat arpen (beat squishies), % bonus arpen (beat fed tanks), and stacking armor shred (takes time or rapid hits). ADCs will be doing less damage, slower, and relying more on crit, which is an indirect buff to Randuin's Omen (and a nerf to their tower-taking power, which BY THE WAY got buffed for AP champions). BoRK got nerfed. Most defensive items with health now give more health.
Everyone's full build got more expensive, but lower tier items are cheaper and gold income is higher. The result is the build paths overall are much smoother no matter what your class or role. These changes aren't happening in a vacuum. You need to observe them in context to properly judge them.