Interestingly I think it’s because Tolkien and Collins were pioneers for their genres. Tolkien is widely considered the forefather of modern fantasy and Collins work spearheaded the wave of YA dystopia which wasn’t as huge a market as it became. In trying to be those writers the ones that came after actually cemented the tropes in the genre. Most of the YA dystopian writers that came after Collins focused on the wrong things, for example YA dystopia went all in on the love triangles, liked how badass Katniss could be making their characters wish fulfilment, and overusing the chosen one narratives. It’s like they were trying to emulate Suzanne Collins but fundamentally misunderstood her work and what she was trying to say