I guess from this post you're implying that Uncharted 4 has a weak start, I actually thought the first 5 or 6 chapters were super strong, and take you through quite a lot,
Boat set-piece > Young Nate & Sam > Prison, Sams "death" > Nate's job / home life > Sam flashback > Heist. I don't think the game really slows way the fuck down until Scotland, which is a very long chapter, although at that point the game really has to sell you on Sam for the rest of the game to work, if at that point you're not into him than I can see how it drags. I guess this game doesn't really have to establish new characters too much beyond a villain, so that probably helps the pace.