> A typical venture fund has a 2% management fee…

> A $100M fund which does 4x earns the GPs $80M ($in carry, plus $20M in management fees)

Nope. 2% of $100M is $2M, not $20M.

> A $1B fund which does 1.5x earns the GPs $300M ($100M in carry, plus $200M in management fees)

Nope.