If you block 3 knives, walk in, you've taken like 5% damage and are close. 3-4% blocking EX Knives is in line with MKX Blocked EX Projectiles. Hardly game breaking. Try blocking Pyro after shroud or Liu after Buffed Fist, both meterless.
The only thing I quoted that you said was that Cyber has some of the best zoning, which is false. It's only good if people don't know how to get in. Liu has better, Kitana has better, QC has better, HQT, has better, etc. The only "zoning" character that has inferior zoning is Kenshi, which isn't saying much.
In a thread of "he needs it", Cyber "needs" that safe Armor'd non combo reversal because he literally has no Mixups in a game where 95% of the cast have amazing pressure and/or 50/50s, weak zoning in a game where multiple characters get 30% zoning conversions, and he has extremely limited options offensively.