At least they have built something and are willing to test it (not like Shawyer), the results will speak for themselves.

Of course, if it doesn't work, there will be a gazillion reasons why it should have, but we will see.

And where is it going? What resources does it contain? Is it even stable enough for mining, "colonizing" or propulsion? Were we able to catch up with it and land on it like on Bennu, an asteroid in our ecliptic plane whose orbit is relatively easy to reach from Earth?

We can't even send people to Mars and have them survive there.

It would be way easier (but still very hard to impossible) to go find a fitting asteroid in our neighborhood and turn that into a spaceship and accelerate it out of the solar system when everything is in place, than trying to catch a ride on some unknown object on a pretty unknown trajectory.

Unfortunately Voyager 6 hasn't been launched. Or fortunately, depending if you want V'ger to turn up or not.