1-on-1, a tank can get cut out by long range attacks or melee, assuming that the tank user doesn't know how to close the gap, or how to kick. Tanks have the scariest kick in the game, for which reason I usually play very carefully around tanks.
As for a 4-on-4 scenario, you simply do not go to the opposing team if they have a tank and your team can't outgun them. Tanks literally tear shit up, in a matter of seconds in cases where proper defense numbers aren't met.
This can go reverse, too. Having a tank with laser cannons for example is a way to force your opposing team into hiding - I got to experience this myself when we were left nearly defenseless on an open-ish map against a LCT and his teammates. Or, it'll get rushed. Who knows.
What tanks lack in maneuverability, they make up for that in damage and toughness. If you can get behind a tank, then, yeah, you're all good. But if you can't, you're all kinds of screwed.
I dunno, maybe you should look up some JP gameplay with tanks involved to get a better picture.
Well, like a bunch of other parts in game, Fromsoft forgot or didn't think right when balancing parts, obviously.
Then again, devs usually have a different mindset from the actual gamers.
There's two sides to this, kinda, the people who develop the products and there's consumers. See where I'm going?
Now sure, they did a bunch of patching for the game but from what I understand, with the servers' already split state (JP, INT), they only listened to the server which actually had activity on it, JP. Now people on the JP kept making demands and requests and said 'this is op, pls nerf, this is bad, buff pls'
And from what I've gathered, this all happened during a period of around half a year? So they kept adjusting the game left and right until they probably went, 'okay fuck this' and left it as is.
So basically, while that probably doesn't have much to do with the core, there's a bunch of parts that people don't use because of how the meta game is.
Nobody wants a TE core with high AP because there is no advantage from that. The AP's going to get shred, like you said, and it weights too much on most frames.
But like so, nobody uses more than 1-2 rifles but even those are really rare. About three gatling guns are useful, three battle rifles,
hell, there's a bunch of shotguns in the game but NOBODY ever uses but one, why? Most other shotguns rely on armor break, but the thing with that is that it requires the opponent to have low enough KE to begin with, but with people stacking for 1600-1870KE benchmarks, it's not really a good damage source.
Nobody uses target guns because people can quickly enter and exit scan mode and blue locking is a thing.
Nobody uses jammers because they're just shit. Except for maybe recon jammers, they can be distracting and make people nervous when you have a pile or a kumo with you.