$4M tanks are defeated by a $40K NLAW. Much like cuirassiers cavalry who were rendered obsolete by muskets becoming rifles with increased penetration, it's not because tanks don't works, it's because it's so cheap to kill one and so expensive to make one.

Until very recently, 2 guys hiding in a bush couldn't kill a tank, you needed a predator drone, an helicopter or some other advanced system requiring heavy logistics. Now behind every bush and every road corner is a potential enemy able to defeat you. With >90% kill ratio for javelins, the tanks needs to be lucky for weeks on end to survive, and the ATGM needs to be lucky only once.