Soccer just has way more fans than auto racing, and astronomically more players from recreational to amateur to professional.

I dont think that Senna can compare to Pele.

This gives and idea of how great was Pele.

Senna is one of the very few people as universally beloved as Pelé here. Since his activity was much more recent he's closer to the heart of a lot of people.

I think Pele and Senna are incomparable.

But Senna captured more of the hearts of Brazilians, in my opinion.

Look at what happened when Senna died [1] and compare to the national reaction now that Pele has died.

Millions have lined up on the streets to say Senna a goodbye.

Of course the circumstance (Senna's crash) has an influence, but still...

To this day, Brazilians still have a hard time holding tears when they remember the day Senna's died.

[1] https://www.youtube.com/watch?v=j79qnfHODPk

That Senna died with an Austrian flag in his car is one of the greatest acts of sportsmanship left uncompleted. (He traditionally drove his victory lap with a Brazilian flag; Roland Ratzenberger, an Austrian, was killed in a crash earlier that same race weekend and Senna expected to win and honor him by displaying the Austrian flag on his victory lap.)

Senna's death was sudden and a tragedy. Pelé's death is also sad, but it was foreseeable given his health condition.