Aragorn the King
Literally a duck
I think if Conk were to rise, it'd be because of its ability to check every Gengar set. It avoids the 2hko from Sludge Wave and always KOs with Knock Off, and additionally doesn't care about Taunt, doesn't mind sub, and actually somewhat enjoys Will-o-Wisp. Destiny Bond is annoying, but it's not that common. Outside of Gengar, Conk also beats Mew with ease, and Mew switch ins on teams with a non-Fire mega are somewhat rare. Guts is actually pretty underrated, since it allows conk to risk much less when pivoting on weaker users of scald/lava plume. It's actually a pretty decent all-around Heatran check, and can also check Greninja reliably now, thanks to Extrasensory's popularity decreasing. Bisharp, Magnezone, Kyurem-B, and Tyranitar are some other relatively common mons that Conk beats.I think Sableye can drop to C+ at this point. It was a bit more hyped when M-Cham was really relevant in terms of that timeframe after the M-Mawile ban. After that though it has become prone to just too many things in the tier. Spikes usage makes its common ability to come in repeatedly to take resisted or immune hits a hindrance because it's forced in so many occasions to spam recover to maintain longevity. Besides the spikes usage in general though Sableye is pretty easy to actually wear down. It's not exactly that bulky, its the illusion that is presented by its typing that makes people assume this when it doesn't want to be taking hits from a lot of relevant threats in the tier. It has a solid niche in having the advantage of burning the majority of physical threats in the meta. However, I've never actually seen a good player get there physical attackers burned by this thing unless they didn't care or it was for another purpose entirely. It slows down very passive stall, Knock Off for a bit added utility, and that's where it shines but Sableye doesn't like such an offensive meta and realistically isn't B rank material.
I posted my opinion on others a couple pages back so that's all I can speak on. Still wondering the justification for Conkeldurr moving up though.
From my experience, it does however have two pretty big flaws. The first is that Drain Punch isn't that reliable for recovery, so because of random burns, crits, hazards, etc, conk can get 2hkod by moves it otherwise wouldn't. The second big issue with Conk is by using it, your team automatically becomes super weak to BirdSpam.
I know conk is pretty mediocre and doesn't deserve the usage it's getting, but I also think C+ is underrating it a bit, just going by definition. By comparison, it has a relatively well defined niche in OU, which sets it apart from Magneton, Entei, Toxicroak, and Infernape (I know that may be vague... but it makes sense in my head. Basically, Conk has a clear role that its able to effectively do thanks to its stats/ability/movepool etc. It doesn't rely on hax or tiny differences in stats to give it a niche). It also faces zero competition for its exact role, which sets it apart from Infernape, Tangrowth, Gastrodon, and Magneton. I'd definitely place Conk way above these mons, but I'm not exactly sure if it's better than Goodra. Goodra is a really awesome Pokemon now, capable of checking a lot of top tier threats, namely Mega Manectric and Gengar, and I pretty much equate its with conk's as an Assault Vest user. I think both, thanks to the rise in Manectric + Gengar + Zone are really solid now, and actually fit better with B- mons than C+ mons.