Alongside an open forum, this will; 1. Reduce friction (no hassle of; finding a developer who will entertain your request and negotiate the terms with the person) 2. People can pool in tokens (other people who have the same problem can also contribute), and Above all, 3. encourage novice developers to participate.
While I agree that you can do this without a blockchain, Web3/tokenization will; 1. Make it easier for cross-border participation; 2. Encourage early participation (you can hang on to your token rewards and see the value increase when the project becomes popular), and ultimately, incentivize the project's advocacy.
Web3 unlocks ownership; by tokenizing the project, you enable the maintainers to own the project.