CA/L are not allowed to be good.
152mm AP shells with ~1600 alpha damage, no matter how good the pen is, will deal no damage to anything but broadside targets <12km.
There is a reason there are two shell types after all.
Speed boost is also useless on cruisers, especially cruisers with a citadel that takes up half of your ship for no reason.
As for Akizuki, I suppose Wargaming decided that having worse shells than Tachibana's 76mm guns six tiers higher (even though there is literally nothing wrong with 100mm secondary's shells) wasn't cutting it. So the easiest way to buff her was to nerf every single other DD that could shrug off her tier 1 shells instead of make her shells better.
Really does make me think...