I think this could solve issues like having a medicine available only to rich countries.
The status quo is a remarkably good match to the requirements of drug development.
You have to not only pay for the blockbuster drug but you have to pay for all the failures.
20 years ago, the average cost of developing ONE new drug (counting failed attempts along the way, testing, certification, etc etc) was north of $1 billion US
I guarantee it hasn't gotten cheaper in the meantime
If it was committed but you could use it until the bounty was met then that's different. But then you end up back at the old pricing model.