This article, like most others, overlooks the primary reason the A-10 has been slated for retirement for so long even though no one contests its effectiveness in its role. Due to the way the aircraft was designed, it has very limited upgradeability compared to most US military aircraft.

While the airframe still makes for a great weapons platform, the sensor suites, avionics, and countermeasures are obsolete, and not in a good way. They've been doing a lot of nasty hacks to allow it to support modern weapon systems and electronics but there are a growing number of important capabilities that simply cannot be "backported" to that airframe.

This has been increasing its vulnerability to more advanced threats and reducing its ability to deploy more advanced weapons over time. Its shelf-life has been extended by virtue of it being used in practice against adversaries with unsophisticated weaponry. This makes it immediately useful in practice but the military is well-aware that it would not be nearly as successful against a more sophisticated adversary and this is why they have been angling for an alternative.

It is a relic of the Cold War not just in its history but, unfortunately, also in its defenses and weaponry with no obvious upgrade path. Its survivability and effectiveness are predicated on being used against Cold War level adversaries. To replace it with something that could support the capabilities they desire, they would need to design a completely new airframe.