I don't know why using Defog/Rapid Spin is not worthy.
You can look at sample teams here for National Dex AG, all sample teams have at least one Defogger.
- The only exceptions would be Sticky Webs or purely Hyper Offense teams which do not always worry about Defogging.
- You haven't provided your team, so I can't tell which Pokemon would do in your team. Regardless, when you know that National Dex AG is full of Smeargle Sticky Webs, Defog/Rapid Spin are always a good idea.
- Smeargle has an usage of 6% and is the #21 most used Pokemon, so Sticky Webs are of concern.
- Apart from normal Sticky Webs, Defog/Rapid Spin support is always nice, considering it removes Stealth Rock, which can deal high amounts of chip to your Pokemon, and some Pokemon (or most) don't carry Heavy-Duty Boots because of item necessity such as offensive Yveltal going for Life Orb over Heavy Duty Boots, or M-Ray.
- In higher ladder, switching is very common, and Defog is important else constant chipping from Stealth Rocks/Spikes can wear down Pokemon especially with no recovery.
As such, Defog is totally worth having.
Some viable Defoggers
Note: There aren't much Rapid Spin users, and most aren't totally viable at all.
Owing to Lugia's high natural bulk, decent defensive typing, and invaluable ability in Multiscale, it serves as a potent blanket check and emergency switchin to some of AG's most potent threats, including Mega Rayquaza, Zacian-C, and Ultra Necrozma. Access to valuable support moves such as Whirlwind and Toxic and Thunder Wave allows it to accrue chip damage or cripple the aforementioned threats, allowing them to be more easily handled.
Having valuable support moves alongside Defog makes Lugia very viable. One point is that owing to the popularity of Calyrex-Shadow and Yveltal, you can opt out for Ho-Oh, but still due to Primal Groudon being the most used Pokemon, Ho-Oh suffers a lot.
Ho-Oh is one of the most consistent pivots in AG thanks to its solid natural bulk coupled with an expansive utility movepool, strong defensive typing, and amazing ability. Ho-Oh can switch into a plethora of common threats, including Yveltal, Zacian-C, and Eternatus, allowing for movepool scouting and wasting Dynamax turns from threats such as Yveltal and Zygarde-C.
Defog lets Ho-Oh provide invaluable utility to its team, helping to keep the field clear of Spikes and Stealth Rock. It also notably protects Necrozma-DM from Assurance Zacian-C, which is particularly beneficial, as Ho-Oh has a good matchup versus common entry hazard users such as Necrozma-DM and Ferrothorn.
- Support Arceus formes
Notable users:
Arceus-Fairy
Arceus-Water
Arceus-Dark
The most common lead and Stealth Rock setter on Nat Dex AG is now Primal Groudon.
Source
The best anti-lead for it would be Arceus-Water and Ground formes.
Rapid Spinners
Rapid Spin should be chosen if running Dual Screen supports, or your own hazard stacks, but there are very few good users of it.
Regieleki and Excadrill
While Regieleki outspeds and revenge kills Kyogre, Weakened zacian-C and Calyrex-Shadow, it's totally walled by Ground types which isn't good news for it.
Excadrill is same, bulky support Arceus formes highly deter it, so it shouldn't be used out of Hyper Offense teams and Gen 8 AG.
Hope this helps!
