If the argument is that widespread technological improvements always come from heavy investment in something so technologically challenging, then why Yet Anothe

If the argument is that widespread technological improvements always come from heavy investment in something so technologically challenging, then why Yet Another Particle Collider instead of the myriad other technologically challenging physics experiments we could be investing in? What's specific to a particle collider that produces these serendipitous side-effect advances compared to, say, a space telescope or other ambitious experiments?