Veigar is single target damage. Of course he does more to single target. He also usually has more AP. When fiddle ults a team, the numbers don't even come close.
Akali is less immediate burst than Ziggs. But she certainly does more than Ziggs, especially with that score. I'm not sure where you got this claim.
Draven is a special ADC. His axes give him added damage. In direct duels he's better than jinx because her damage comes from Aoe rockets. Still, 5/1 jinx will beat 0/3 Draven most of the time. Confused with this claim as well.
Yasuo is just wrong. In no world does yasuo out damage riven, especially 7 kills. Same with fiora.
0/10 Teemo won't "got" a 20/0 garen. That's an easy garen win unless severely outplayed.
I really don't get most of these comparisons. Only one that had any merit was veigar and fiddle, the rest were just baseless claims. Veigar can still have more AP because he farms AP and his ult is a single target nuke.
Kills and deaths don't tell the whole story anyways. Farm is a huge factor, towers taken, etc. all champs also have a power budget. The one with higher kills isn't meant to do more damage. Itemization is also a factor.
You have a lot to learn. Easier to learn from mistakes instead of blaming the system.