That sentence made me laugh really hard. I don't know if you are blind or you are just trying to defend stall and every fucking defensive pokemon in every single post you make.
Chansey's usage became disgusting high in a very short time span. Special attackers ARE a deadweight when chansey is on the team, period. Chansey limits teambuilding to a degree where you cover the tier's all special attackers with one poke, then you just take mixed walls/ physical walls to cover other threats and there, stall triumphs once again. Jolteon HAS to run fake tears to at least have a chance of defeating Chansey or force it out. Espeon will get toxiced while calm minding, Chansey doesn't care about status due to NC. Charizard can defeat Chansey only under very specific circumstances: it has petaya, blaze activated, it's modest, and it's under sun. Then yeah, it has a chance to OHKO (!) Chansey with a STAB Sun Blaze +1 Fire Blast (or guarantee the OHKO with Overheat but that's bad). Magneton has little hp, Chansey usually switches in on Sub or TBolt, Magneton has to Metal Sound afterwards to have a tiny chance of 2HKOing Chansey with TBolt while it can wish protect and seismic Magnet away.
252+ SpA Magneton Thunderbolt vs. -2 252 HP / 0 SpD Chansey: 163-193 (45.6 - 54%) -- 3.9% chance to 2HKO after Leftovers recovery
Oh wait all Magnets are grass/ fire
248+ SpA Magneton Thunderbolt vs. -2 252 HP / 0 SpD Chansey: 162-192 (45.3 - 53.7%) -- 2% chance to 2HKO after Leftovers recovery
Totally worth taking my chances.
I am really fond of using special attackers in OU but Chansey limits me to such a degree that I just don't bother anymore. I know you love stall and OP defensive threats Zeb but take OU's healthiness and be objective at least for a moment, then say to yourself "this shit has to go".