PSA: Just because the Metagame counters your main champ, doesn't mean it counters your category
Nearly every class has a subset of champions that fares incredibly well at countering another class while not being as good of an all-round pick.
If a class that generally beats out yours becomes the meta, the "all- round" picks of your class will be bullied out, while the "specialist" picks will shine.
For example: early in season 4, the AD bruiser Bully/Splitpush meta was bullied out by extreme tanks due to an itemization shift. The all-round picks like Tryndamere found themselves struggling against the standard tanks like Mundo and Nasus, who could ignore them at early levels thanks to Doran's Shield. Because of this, Trundle, a bruiser specialized in fighting tanks, had a period of popularity before the tanks got Nerfed.
The same thing is happening everywhere, all the time. Super mobile early bully junglers are the norm and late game picks are being bullied out? Rengar is still strong because of his early dueling power despite a really important level six power spike. High poke midlaners become the norm? Yasuo is near-permabanned because he's almost a perfect counter to that meta.
Get creative with your picks, and know your specialists.
Bruisers: anti-tank, Trundle, Darius. Anti-assassin, Garen. Anti-range, Irelia, Wukong, Pantheon
Every class has its ups and downs. Sometimes, yes, only the specialists can be played. Several classes, like poke supports and tanks, have been bullied out for so long that all people recognize is the few specialists that have been consistently playable. But it's very, very rare that an entire class is so bullied that they're out of the game entirely. I would argue that it's almost never happened except in extreme hot fixed imbalance cases like League of Cleavers and the Week of Targons. So keep your head up-you don't have to give up your favorite class to avoid having an unfavorable lane matchup every time.
)