Idk. Most people who get THE results (MMR2600+) kind of agree that Arachnas wasn't a thing then, and is now, because of buffs and meta shifts. But Arachnas might go down verey easily. All it takes is teching in row punish. It's expensive and bad, but totally destroys Arachna's round dynamics when well placed.
I can agree that Arachas swarm got some nice buffs with spontaneous evolution and the buff to crimson curse (and ekimmaras). And yes, in this meta, going wide is definitely not as risky as going tall, but i still argue that is the case for most metas in the past 2+ years.
I've been on the receiving end, and definitely dont want to be matched with arachas opponents, its one of the toughest matchups, even if im using tier 1 Lined Pockets with drill and freakshow, because paying 2 to kill 1pt drones sucks.
The deck i've had the most success vs arachas is my elf traps, havent lost a single time since the traps completely counter arachas, specially with the spring option. And also my DW deck, since it swarms faster than arachas, then they dont know what to do with their Yen which is usually the biggest pointswing.