To me Latias is that Pokemon that is just so great on paper, especially when team building, but is disappointing in practice. It really comes down to this when placing Latias on a team: she closes as many holes as she opens up. In early BW2, it was evident that Latias could stop those nasty threats like Breloom, Keldeo, Special Lando, Thunderus-T, and a general rain/sun check. I made it almost a rule to include her on almost everyone of
my teams at that time period and
others. Since then, the metagame has matured and most teams have adapted to her presence to check threats. Really, using her is opening yourself up to most standard teams.
Take your cookie cutter Sand team for example. Considering that everyone and their mom are using RP Landorus
with Tyranitar I would not rely on Latias to be my Lando-I counter. To quantify that for you with the usage stats, Tyranitar is by far Landorus-I's most common partner at
33.9%, 20.9% over the next closest Terrakion. How about your average rain team with Keldeo? You will either find yourself becoming setup bait or crippled at the hands of Ferrothorn or Jirachi since you are so incredibly easy to check lol@HP Fire in rain. Should I even address the issue of being weak to U-turn? It is not only Scizor's OHKO U-turn I am concerned with, it is becoming the crux for other Pokemon to gain momentum on you.
My second beef with Latias is its quandary between speed, bulk, and power. You can only pick two of the three and each combination has its consequences. Without enough speed, essentially Max speed, you lose the ability to counter Thundurus-T, Landorus-I, and Keldeo. They will all be able to cleanly 2HKO with HP Ice. Not enough bulk aka max HP? You lose the ability to keep up with taking hits from the Pokemon you are supposed to counter in the long run during the match. If your opponent switches out to give you a chance to recover, it still is a lose of your momentum. No investment in power? Watch as half the tier laugh as they nullify your attempts to set up. Your pitifully weak Dragon Pulses and coverage will only get you so far in a tier full of Pokemon with U-turns and a game where the #1, #3, #4, and #8 Pokemon severely cripple or trap you.
In short, my problem with Latias that whenever I use her, I feel as if my position is never improved. Latias' need to recover constantly if it is the LO set to check threats, inability to cause immediate damage with the bulkier CM sets, and weakness to U-turn (switch initiative)/Pursuit (elimination) never puts your opponent on the rocks. Ultimately when you using Latias to check threats, you are not the one controlling the match.
And to those who might say "But Pillsbury you just
don't know how to use Latias" I peaked pretty high with it during the
BW1 era. So I can say with confidence
I do.