Actually, hard body armor (trauma plates) can tank a pretty surprising amount of punishment before failure. To be quite honest, at least on the security side, both light and heavy body armor could realistically tank every ballistic weapon in the insurgent arsenal, including AP rounds with exception to the DShK mounted on Techies. ESAPI plates are no joke.
That being said, the INS team got the raw end of that bargain, as it looks like their light armor is soft. With exception to pistols and non-flechette shotgun shells. The MP7's caliber is optimized for defeating soft body armor though, and it's probably punching through despite being a pistol cartridge.
If you want to see a realistic example of body armor in FPS games, and specifically why it's horrible for balance, I present Escape From Tarkov. https://www.youtube.com/watch?v=jc9QdU-tn9o&t=122s
First world nations don't equip soldiers in body armor just to piss away tax dollars, and our guys aren't getting 1-tapped all the time either.