People will be more interested if they see how the stuff they are learning is useful.
Useful 99% of the time means you can make money with it.
Projects don't need of course to reach the level of novel result. But they must at least aim at moving towards that.
And if you really can't make money from a subject, there is only one other thing people crave: beauty.
You have to give the beauty motivations upfront, before boring people to death with endless prerequisites, otherwise no one will ever want to learn it.