Im of the view that economics - rather than technology - is the stronger objection to alien visitations. Even allowing that advanced ETs have the knowhow to build intergenerational starships or near-lightspeed starships or a network of artificial wormholes, such undertakings would be enormously expensive (in effort, time, resources). And for such hypothetical ETs, nothing that Earth has would be worth this investment. Now, if they just want to say you are not alone or generously provide us with the Encyclopedia Galactica (to accelerate our progress), this can be done with radio (or similar) communication. No costly (physical) commute necessary.