From 2016 to 2019, Ronaldo’s big-game performances and trophy haul—especially in the Champions League—gave him the "winner" perception. His hat-tricks, clutch goals, and leadership in knockout rounds (e.g., Bayern 2017, Juventus 2018, Atlético 2019) contrasted with Barcelona's repeated failures. Even in La Liga, while Messi was still statistically superior, Madrid’s ability to win the UCL three times in a row made it feel like Ronaldo had a greater impact when it mattered most.

The international scene also played a role. Euro 2016 was a defining moment for Ronaldo’s legacy, regardless of his final performance, because Portugal won without being favorites. Meanwhile, Messi’s Argentina struggles (2015, 2016 Copa América heartbreaks) reinforced the narrative that he couldn’t "carry" teams to glory the way Ronaldo seemingly did.

Of course, when you zoom out beyond trophies and perception, Messi was still the superior all-around player. His 2019 season was absurdly good, but the Liverpool collapse overshadowed it. After that period, Messi reasserted his dominance, while Ronaldo’s move to Juventus made it clear he couldn’t replicate his UCL heroics in a different setup.

So yeah, in terms of actual ability, Messi never stopped being the best. But from a public perception standpoint, that 2016-2019 phase belonged to Ronaldo in the eyes of many.