I think Tiger's dominance during that time is what makes people say he's the greatest ever. Think of how many more majors people like Ernie, Vijay and Phil would have won if Tiger wasn't around.
You can't discount his 2019 victory. Go look at the list of players with one major win. Or even players with no majors. Players like Love, Duval, Furyk, etc. household names who won once, in their prime, and Tiger wins in his 40s after having spinal fusion…. It's amazing no matter how you slice it.