Only within the limits imposed by our current technologies and understanding of science. A paper came out recently claiming that the Universe is double the age we’d had assumed. Science changes the boundaries of our understanding all the time. What we do know now is that our little planet is fairly unique. There is radio silence out there. That clearly makes us very interesting to any advanced civilisations in the Universe.Agree totally with this. FTL travel is almost certainty impossible without turning said travellers in to mince meat.....there certainly are other intelligences out there, the chances of two being within travelling distance, hugely unlikely.
But I get your point. If they have travelled here, they’ve not done it via the conventional spacetime route. The accounts of the UAP suggest that also.