Teleporting makes more sense than traveling hundreds of light years even with Warp drives. The interstellar medium is not void, at high speed there will be a lot of friction making it impossible to reach long distances.
Time travel would anyway necessitate some sort of teleporting as the Earth is moving at high speed (447,000 miles per hour around the Milky way). So going back one century would mean having to jump a distance as far as Oort cloud. So any entity that could do time travel would be able to travel to other stars as well.
Any comment?
All so-called UFO/UAP/alien visitors have more plausible explanations: human fallibility, gullibility, hoaxes, hallucinations (drug induced or otherwise), atmospheric and other natural phenomena, reflections, aircraft, balloons, etc. etc. We have no evidence of visitors from other planets. None.
I really doubt "the government" (and not just ours -- all of them) could maintain a conspiracy of silence involving tens of thousands of people for over half a century. And I doubt an intelligent species would go to all the trouble to visit us only to sneak around and dissect cattle.