Ballon d'Ors are one thing, with the pair sharing 11 between them, but achieving success with the national team has been critical to the grander standing and legacy of the two outstanding players of this generation.
The late Maradona, of course, took La Albiceleste to World Cup glory in 1986, which has eluded Messi who was a runner-up in 2014.
Messi was part of the Argentina sides that lost Copa finals in 2015 and 2016. He briefly retired after missing his penalty in the 2016 final shootout.
This tournament was his sixth shot at lifting the trophy. And it was the 34-year-old's best yet, dominating as joint top scorer with four goals and topping the Copa assists charts with four.
Messi was not the star in the final, with a lively Angel Di Maria scoring the winner with Argentina's first touch inside Brazil's penalty area.
Udinese midfielder Rodrigo De Paul set up the winner and was a key presence at both ends, while goalkeeper Emiliano Martinez was the star in the semi-final shootout and exceptional again in the final.
But Messi was the big story. The Argentina captain and superstar has taken a huge weight off his shoulders with international glory.
Argentina fans will start dreaming about what is possible at next year's World Cup in Qatar.
Lionel Scaloni's La Albiceleste are unbeaten across 20 games and conceded only three goals at the Copa America.
Argentina scored 12 goals across the seven games in the tournament, with Messi directly involved in nine.
The final was billed as Messi versus fellow superstar and former Barcelona team-mate Neymar, who was busy but closely marked throughout by the Argentines in the final.
Neymar, who missed Brazil's 2019 Copa triumph, is another global superstar yet to lift the World Cup or a continental title. Missing out on home soil will be a great disappointment for the Selecao.
The loss was Brazil's first at home in 25 games under Tite (W21 D3 L1). It also ended their 13-game unbeaten run.
The margin between victory and defeat was fine, but the fallout for Messi and Neymar is a stark contrast. Ecstasy and pain.