Still best player in world in 2021.
This is laughably absurd and demonstrably false.
1) KO'd in the quarters of the most prestigious competition.
2) 3rd in the domestic competition.
3) Not the golden shoe leader.
4) Not the CL top scorer.
5) Lost against both Real and PSG at home in 2021.
By what measure in the world do you simply wave that away?
Ronaldo is in the same situation (4th in the league, out of the CL, etc) and,
rightly, noone is claiming he is still somehow the best, even though he, like Messi, is the top scorer in the domestic competition. This is not 2012. Neither of them is the best.
In 2021 Modric, KdB and Mbappe are all playing better and delivering decisive performances when it matters.
As in every other sport, that is the standard for determining who the best player is.