Given that your sentence is in the present tense and given the space-time distance to other stars and galaxies, evidence supporting such a claim would seem to be limited to actual visits to Earth by extraterrestrial beings.
Life exists, extant. They either got off their planets and acheived interstellar travel, or they did not and snuffed themselves out.
So the question is, if any carbon-based water-dependant sentient group (who either likely partially or completely merged with silicon-based devices, as the singularity will occur here on Earth long before interstellar travel), achieved interstellar flight, did they come here, or did they ignore us, or are they running the clock?
Or, did it happen in a different galaxy, say SPT0418-47, and the nimrods are content to move from place-to-place within their neighborhood using Direct Fusion Drive or nuclear pulse or light sail at a reasonable speed-of-light, but don't see the purpose in intergalactic travel. When you look hard at Drake and Goldilocks [CHZ], that seems a like a reasonable concern. An abundance of primitive life in almost every Goldilocks zone (panspermia), an ever-dwindling amount of sentient life per the needs of 'rare earth', the moonshot that creates bipedaled carbon-based humanoids; and of course they all end up separated by most of the universe.