Zardnaar
Deity
T-14 has ~50 production models in existence with the rest of the line being cancelled, I'm not sure it's even valid to compare
Firepower doesn't really matter because tanks don't fight other tanks and haven't since the 80s (Iran-Iraq). Hence why armor is the most important. Mobility is great to have, too, but you're not going to be outrunning a TOW or worse, a fire-and-forget missile system. Armor or other survivability countermeasures have to be #1 consideration for the modern tank.
I lean this way but would need to read up a bit more on the Challenger.
Even if Abrams gets penetrated to still have a reasonable chance of no dying horribly.
It's a bit harder to compare Challenger 2 as it hasn't been used as much or had actual tank battles which did happen GW1.
It's not so much crappy T-72's couldn't see let alone penetrate the Abrams more how fast they took them out while driving 50kmh.
And that was almost 30 years ago.
Armata was likely to expensive, didn't work or work well enough outside test conditions to justify the cost.