There is a limit to how big we can build particle colliders on Earth, whether that is because of limited space or limited economics. Since size is equivalent to energy output for particle colliders, that also means there's a limit to how energetic we can make them. And again, since high energies are required to test theories that go beyond the standard model (BSM) of particle physics, that means we will be limited in our ability to validate those theories until we build a collider big enough.