Right, but that’s still $1 million per tank on top of the already high cost of the tank’s Chobham armor, to protect one 120mm gun and three machine guns. Not to mention the logistics of transporting, fueling, and maintaining it all. Also, while it is reportedly very effective against individual missiles, how well will it handle saturation by larger number of cheaper missiles or drone swarms, which aren’t too far off in the future.
Tanks are not yet obsolete, but they are well into their senility.
One indicator of how well various APS may do against missile swarms is provided by the Second Chechen War. The Chechens found that against tanks with the then latest Arena APS, they had to fire at least six heavy ATGM in a saturation attack to have a reasonable chance of getting just one hit.
It is also likely that with the APS, tanks will evolve to be lighter and less expensive/less heavily armored. At least in the latter case, it will echo naval development, where anti shipping missiles have made armor above the level needed to repel small arms and maybe 40mm fire pretty much pointless.