Right now we're looking at Clefable from the perspective as a support Pokemon in terms of what it's capable of and the possibilities and traits that it can provide as a team asset in the current meta-game as of right now. What the focus has been in response to Clefable to going to S has mainly been its power output when used as a comparison amongst both the A+ and S rank Pokemon. Realize that a Pokemon's placement is also dependent on the utility it can provide for a team in regards to threat control, a team's overall effectiveness as either a defensive or offensive asset, as well as the effectiveness of the Pokemon itself.
First of all, clefable's stats suck. It's really only saved by it's typing and two abilities. It's bulk is actually not good for a defensive mon. For clefable to be able to switch in to the mons that it beats, it needs to be at full health or near full health. Often times having to take a few stray volt switches or u-turns, or a weak resisted attack can be the difference between clefable being able to safely switch in or being 2HKOed. A simpler way to put it would be that clefable really needs to be at full health to function well. I don't know if anyone else has ever noticed but in many games I just notice myself having to keep spamming softboiled just to keep healthy and often times you'll just be giving away free turns by doing that.
Besides that, you can easily slap one on your team as it covers a good portion of the meta and has good synergy with a lot of mons. It can fulfill many roles that other pokemon can't, such as being an SR setter, set up sweeper, cleric, wish passer, and check to a lot of mons. it’s the perfect utility mon in a sense that it can always get up sr and beat all spinners/defoggers. it’s ability + typing make it an excellent pivot or sweeper as well as a valid move pool to boot. if it wasn’t for its “poor stats” i think it’d be too much to handle. it has great utility in sr, twave, knock off, healbell, encore etc. the unaware version stops set up sweepers and clefable is just a mon that can be slapped on to any type of team. it has solid recovery in soft boiled/heal bell and two amazing abilities.
Definitely support this. Clefable's ability to fit on so many teams as well as offering tons of support and utility makes it a pretty much no-brainer S rank. The thing really holding it back from being Uber is its mediocre bulk, forcing it soft-boiled/moonlight often. Pokemon can be judged in 4 different areas: Ability, Movepool, Stats and Typing. Clefable excels in 3 of those 4 criteria. Clefable is also an extremely reliable stealth rock setter, as it is pretty much able to beat every defogger in the tier. Clefable can also serve as a reliable but scary win condition against stall and balance teams with its calm mind + magic guard set, which can be extremely difficult to stop once it gets going. Unaware Clefable can also act as a blanket check to multiple dangerous sweepers in Sketchmons, such as Quiver dance users like Manaphy, Thundurus, Keldeo, Diancie, Belly Drum/Shift gear Azumarill, Landorus-Therian, Garchomp ect, dragon dance altaria, calm mind mega sableye, calm mind ratios/mega latias and dragon dance gyarados. However, what I think puts clefable in S is its sheer adaptability. Clefable has the ability to surprise nearly all its checks with a coverage move, as well as run tons of different very viable sets, making it an unpredictable opponent to face. Some examples of this are ice beam for gliscor, thunderbolt for talonflame, focus blast for heatran, knock off for gengar, fire blast for ferrothorn/scizor/excadrill and thunder wave for a ton of sweepers and encore to turn set up pokemon into liabilities. Clefable is just so adaptable, dangerous and splashable that I fail to see the relevance of many of the counter S arguments. It's ability to shift arounds its EVs to counter a plethora of threads is amazing in the current metagame, gaining reliable recovery and a great set up move is a god scent, Will o Wisp can be used to cripple threats that'll overpower it.
Edit: If Clefable had 10+ In each of its stat it would get quick banned. Its stats are literally the only thing holding it back.