In general, vendors come up with their own solutions first and then switch to googles solution once that is mature enough. It's just how Android works and also why nobody releases (stable) os updates until 6-9 months after Google's announcements.
Samsung has recently been pretty good at security updates (which is different from OS updates).
Huawei, Lenovo and the rest are at the bottom of my list. Sony, Google, Nokia and surprisingly One Plus are at the top.
