That wiki doesn't justify your statement. It's leveraging a list from 2017, but using Alphabet's market cap from 2019? And regardless, the actual market caps on that page would say Microsoft is the biggest software company in the world.

I have no idea what Forbes is using for its ranking but it is obviously not by valuation.

EDIT: And it should arguably be Apple, but for some reason neither Apple nor Amazon are software companies?

The Wikipedia article sorts by sales. Not sure why the years are like that, but the relative values are similar in 2019. [1] [2]

> for some reason neither Apple nor Amazon are software companies?

Because they aren't software companies? Or at least principally software companies.

Amazon is categorized as an retail company. [3]

Apple is categorized as a computer hardware company. [4]

Nitpicking aside, I think my point stands about a $800B+ company.

[1] https://www.forbes.com/companies/alphabet/?list=global2000#5...

[2] https://www.forbes.com/companies/microsoft/?list=global2000#...

[3] https://www.forbes.com/companies/amazon/?list=global2000#2c4...

[3] https://www.forbes.com/companies/apple/?list=global2000#3d04...

And market cap while it measures investor sentiment, doesn’t measure fundamentals. If it did, Uber wouldn’t be worth anything.