Isn't it just usual that a project should have a fundamental that makes sense as a start?

Investors won't just throw money if the project doesn't have a reasonable fundamental use-case. If the team were able to show that clearly and the roadmap somehow made sense, investors might think that it's worthy investing in. The next one is the critical part, how the team will manage the project along the way and that's the key in making a strong backed community around the project.

It's really tough to choose a project especially risking money for startups that's why a good-decision making should always be a priority.