It was around the S2 tank/diver meta where you had adc's building Randuins (70 armor 500 hp) Banshees veil (not the ap version we have now, it gave hp+MR) and sometimes warmogs (it gave 1500 hp). Shortly after this meta we had the adc's building Spirit visage/warmogs meta because well randuins and banshees got nerfed. But then warmogs and visage got nerfed too.... (They also killed FoN "We don't want healing to feel silly", so they gave a silly passive to warmogs that requires you to get out of combat... yea great...)
Everyone had so much defense, and defense was so high that you couldn't just one shot anything with anyone. That is unless someone skipped getting randuins/banshees.
TBH I know why they got rid of that meta, it was super boring to watch nothing happen for the first 30 seconds of a team fight, just for someone to finally die. But I did really enjoy playing the game back then, because 1 lux rotation didn't mean I died, 1 talon rotation didn't mean I died. I did however die once from full hp to leblank... she DFG'd me and hit every single ability as I hit my ulti as mundo... me using my ulti is actually what killed me because the damage hit .5 seconds after the hp cost was deducted (whoops).
I loved that you could build enough armor to ignore ad champions entirely and auto win just because the enemy team didn't pick a mage. Back then we didn't have mindless mashing of buttons (well except maybe garen/sona) you actually had to think about your team comp (for mixed damage), and adc's were balanced on kiting, Assassins were balanced on finish off players at somewhere between 60% hp. CC didn't mean you died, you just waited for it to end. Tanks were big fucking meat shields that would take skill shots for their team (now I don't dare block shit, they better dodge). Sure we had issues back then, but it was mostly localized to 1-2 over tuned champs. (or bugs, like the huge aoe bug where karthus/talon were suddenly gods, or the LB bug where she could instantly kill you by using her ulti, yorick never dying bug and etc... )