You're putting the cart before the horse; until you change the government and thus the bail system, we need bondsman. Making bounties illegal won't stop judges from setting bails people can't afford and is thus not a valid solution.
In a country where judges are elected a multi billion dollar has a lot of power in determining how bail is set by the courts.
If you think that judges that get donations from bondsmen don’t take that into account when setting bail you are very naive.
This is the exact same problem as private prisons the justice system should not be monetized for profit.