They're silent because they finished their investigation two years ago. You can google this (but please not on conspiracy theory websites).
The Dutch-led investigation concluded, way back in 2016, that "the airliner was downed by a Buk surface-to-air missile launched from pro-Russian separatist-controlled territory in Ukraine. According to the JIT, the Buk that was used originated from the 53rd Anti-Aircraft Missile Brigade of the Russian Federation, and had been transported from Russia on the day of the crash, fired from a field in a rebel-controlled area, and the launcher returned to Russia after it was used to shoot down MH17. On the basis of the JIT's conclusions, the governments of the Netherlands and Australia hold Russia responsible for the deployment of the Buk installation and are taking steps to hold Russia formally accountable."
