Yeah but Leo already received individual honours, largely based on the WC. The WC golden ball ofc, the FIFA Best award, the IFFHS Playmaker of the year etc. Despite being really bad in the 2021/22 CL KO.
If you even look how the WC influenced the Ballon D'Or voting the past years, you see that 'rarely' the Ballon winner actually won the WC.
2018 -> Modric (you could give it to Griezmann or Mbappe. Neither of them had monster seasons, but that applies to Modric too)
2014 -> CR (CR dominated the CL, it did not help that Neuer conceded a bunch of goals in the CL semis)
2010 -> Messi (the story has been discussed over and over, but you could give it to Xavi or Iniesta if we applied the rule)
2006 -> Cannavaro (the exception to the rule and ofc it is still discussed to that day. R10 had won the CL+La Liga double with Barca and was arguably the best player in the world at that time. But the thing is, that Brazil team was hyped to win b2b and rightfully so. I think they remain one of the most talented NTs ever on paper. And R10 was the best player in the world, he was expected to lead them to the title and failed totally. So, you can see the point...)
2002-> R9 (I don't think that counts as an exception to the rule. Yeah R9 did not win the CL (presumably he did not even participate in it?). However he was the leading man for Brazil + he was coming back after a monster injury + he was one of the most hyped/talented players ever + he completed a big transfer to Real Madrid and presumably had a decent start to the 2002/03 season etc. On the other hand, France did not even make it to the WC KO, so Zidane and Henry had to be ruled out.)
1998-> Zidane (won the WC and made it to the CL final with Juventus + was among the 2-3 rising stars in world football. )
And before that, non-European players could not even compete for the award, so there is no point discussing it any further.
I mean the last 15 years, the B'Dor has gone to the CL winner 10 times, this also a quite important precedent. The remaining 5 times, the B'Dor winner reached at least the semis 4 times. If we also count 2020, which would go to Lewa without a doubt, then in the last 16 years: 11 times to the CL winner and 4 times to a CL semifinalist.