China and India are the outliers. For most people, pre-pandemic (and post financial meltdown), the wait was under 2 years - almost everyone I know got it in under 2 years (EB-2, MS or higher degree).
If you weren't born in China/India, and had an "advanced degree" in a STEM field (i.e. MS or higher), the green card process was/is fairly smooth. The real bottleneck is the H1-B visa quota/lottery.