>>54190068BW is deeply different than ORAS. Permasand means cancer stuff like Suicune and Zapdos aren't durable enough and there is only 1 decent spinner, Excadrill, that still loses to common SR setters anyway (lando, chomp, even loses to ferrothorn if it hits 2 power whips etc), therefore Stealth rock is almost always up.
I'm not gonna lie though Zapdos while not OU by usage still was pretty decent for a while in rain teams, where it abused pressure by spamming substitute and ofc thunders. Basically you could use it against ferrothorn to trade 3 layers of spikes for 1 or 2 guaranteed kills which is good because rain teams could always spin everything away with tentacruel later.
Zapdos itself also has very decent defensive qualities, being one of the like 4 mons that can check Tornadus, while also being immune to Ground and having a really strong hidden power ice.
It fell off due to a variety of factors: the rain teams that were able to use zapdos usually had some troubles against stuff like reuniclus, also extremely fat sand teams with protect gliscor, ice beam gastrodon, or those with sdef protect excadrill can dance around it without many problems till it loses all its hidden power PPs, other than having the basic counterplay of sending tyranitar in to delete zapdos' leftovers recovery.
Thundurus-T is just more reliable at breaking defensive cores even though it can't check Tornadus due to its shitty sdef.
Also we never got the Dream World ability, which was Lightningrod at that time, which maybe could have had interesting applications
