What is wrong with Goths? (noob here)

So I've been playing various forms of multiplayer recently, including ranked matches and custom scenarios. What always stands out to me is how good the Goths seem to be. They seem to have the perfect easy counter to anything, are really fun to play with, and at their strongest are pretty hard to beat. Huskarls are literally OP: fast, immune to arrows, bonus vs buildings AND archers, cheap, can be created literally instantly especially with a drop barracks. They counter perfectly archers, castles, towers and just are in general a decent melee option. Their super fast barracks produce halbs next to instantly as well, so what huskarls lose in their vulnerability to cavalry and elephants, halbs make up for in sheer numbers and cheapness. While a pro player might argue "ooh but they're early-game eco is weak", for most games that get into the late-castle / early-imp, Goths seem perfect. I am a pretty nooby player, so can someone tell me where I'm wrong?