First of all, I just want to report that I just played a team with Skrelp and Houndour on the ladder, so it doesn't seem like they're properly banned right now.
As for the Sticky Web suspect: Has this tier really been explored enough for us to answer this question? There were 57 total ladder battles in July. I'm sure there are plenty of battles outside of the ladder, but unless people have been going crazy with LC UU outside the ladder, LC UU is far from a fully developed metagame. In my personal experience, I haven't even seen much Sticky Web at all. I've played 10+ LC UU ladder battles and I've seen one other Sticky Web team. (Full disclosure: I have used Sticky Web in all of those battles, although that's honestly 100% because Cubone is my favorite pokemon). It's hard for me to justify banning an entire playstyle on the basis of such little evidence.
With that said, I would be against any Sticky Web ban on a theoretical basis as well. I want to especially dispute the following point:
the tier's spinners and defoggers being easily checked by Pumpkaboo and Mankey respectively, making them unreliable at their jobs.
Anorith, despite appearing in only 8 combined ladder battles in the last two months, is a very reliable spinner. First of all, it can function as a nice anti-lead to Spinarak, OHKOing with 3 hits of Rock Blast (rarely OHKOs with 2). It takes little from Poison Jab and can survive Megahorn with Eviolite or with Berry Juice + some HP investment. Once Sticky Web is down, Anorith still hits 12 Speed, which allows it to outspeed Pumpkaboo and usually 2HKO with Knock Off:
156 Atk Anorith Knock Off (97.5 BP) vs. 84 HP / 236 Def Eviolite Pumpkaboo-Large: 10-14 (43.4 - 60.8%) -- 88.7% chance to 2HKO
And Anorith is not the only option. There are actually several spinners in LC UU that can heavily damage Pumpkaboo on the switch in:
156 Atk Sandshrew Knock Off vs. 84 HP / 236 Def Pumpkaboo-Large: 10-14 (43.4 - 60.8%) -- 88.7% chance to 2HKO
196+ Atk Kabuto Knock Off (97.5 BP) vs. 84 HP / 236 Def Eviolite Pumpkaboo-Large: 10-14 (43.4 - 60.8%) -- 88.7% chance to 2HKO
204 Atk Bergmite Avalanche vs. 84 HP / 236 Def Eviolite Pumpkaboo-Large: 18-24 (78.2 - 104.3%) -- 6.3% chance to OHKO
Unlike Anorith, Sandshrew and Kabuto do not outspeed after Sticky Web and thus cannot afford to stay in for the 2HKO, but both can remove Eviolite and put Pumpkaboo within kill range. Even Tentacool can hit semi-cripple Pumpkaboo with Knock Off and then hit fairly hard with Ice Beam.
As for Defog, I don't think Mankey in LC UU is nearly the counter to Defog that Pawniard is in LC OU. Unlike Pawniard, Mankey doesn't have the benefit of priority. It also doesn't have Pawniard's great defenses and typing and is OHKO'd by many of the Flying-type Defog users in LC UU. Some of these prospective Defoggers either outspeed (Doduo, Taillow, Wingull) or speed tie (Rufflet) with Mankey, meaning they can Defog as Mankey switches in and still OHKO before Mankey has the chance to do anything (as long as it isn't Scarfed of course).
Finally, Rapid Spin and Defog are not the only ways to beat Sticky Web. Taunt (Meowth, several others) can help. Magic Bounce Natu can be extremely hard for Sticky Web teams to play around. And then there are Pokemon (Inkay, Flying-types) and playstyles (Sand, Trick Room) that to some extent bypass or even benefit from the effects of Sticky Web.
tl;dr: There are tons of potential answers to Sticky Web. These options have not been sufficiently explored for Sticky Web to be banned at this time.