Is it just me, or do IFV cannons seem way too effective?

It was always my understanding that the 20mm and 30mm cannons used on vehicles like the BMP’s, BTR’s, and Bradley’s were designed for use against lightly armored targets. How is it that they are so deadly against MBT’s? I recently had a BMP-2 hit my Type 74G frontally with two rounds and take out my tank.

it is more that most cannons are nerfed (those beside russians), and the 2 hits on BMP are way more propably they got the highest rate of fire, first thing that is nerfed is that they now need way more hits to destroy the cannon barrels now, but the biggest problem for most IFVS is that Bradleys, Puma often have less ROF then BMPs and on top of that compared to BMPS they overheat to fast and their accurary should be way higher because they fire slower.

Generaly it is unlikely that IFVs will frontaly kill you with cannons that is what their mounted missles is for, sometimes they just will get trough most noticeably with fast firing cannons because they have more hit checks so to say. And they get APFSDS to penetrate tanks specialy as well, for lightly armored targets he rounds would be more effective