Cancer research needs brain power.
Of course, brain power costs money.
However, funding cancer brain power by transferring brain power out of cancer seems like a broken window fallacy.
The reality may be that there is a decent amount of brain power to go around but I can easily agree that any brain power spent of ads would have been better used if such a money printer were not allowed to exist.
With that, I can see the continued existence of advertising work as something that ultimately removes more value from the economy that it creates.