its the black swan problem of induction. no definitive solution has yet been found; in fact iirc the possibility of a perfect solution has been disproven. this impossibility can be and has been used to justify any number of absurd and improbable positions, notably religion. you will have to settle for ‘good enough’ on this one. also, if the competition already exists in this space and is so hard to find, then the niche for your project seems open.
the best you can do is make the best effort you can think of. industry-relevant repositories, github was a good start, word-of-mouth with relevant industry partners and universities. if the alternative to your project exists but is that hard to find, id say your niche exists regardless.