That's of course true, but it's might be misleading. OoO didn't take off until HPS came up with the reorder buffer (and enabled precise exceptions), with Penti

That's of course true, but it's might be misleading. OoO didn't take off until HPS came up with the reorder buffer (and enabled precise exceptions), with Pentium Pro being the first (and highly successful) implementation. Also, branch prediction has dramatically improved since stretch, McFarly's two-level was a breakthrough and the current state of the art is Seznec's TAGE-SC. My point is that there's still a lot of advancement made.