An important distinction between Polar vs. traditional bounty services though and regarding your point is:
Everything goes through the maintainer(s) and we're equipping them with the insights, capital and tools to reward their contributors. While bounty services allow anyone to post a bounty and anyone to pursue it. However, ultimately it needs to be reviewed, merged and maintained indefinitely by the maintainer(s). By ensuring it all flows via maintainer(s) it:
1. Rewards maintainers as well – key given their efforts
2.Guarantees maintainers are aligned & behind pledges first. Combined with in control on how to expose, delegate and reward it. Avoiding unnecessary friction, bad faith and overhead if such alignment is first made during PR.