Is travelling to distant solar systems actually possible?

Let's say it was just a robotic space craft with only some samples of dna that it would then grow in artificial wombs when it got to the next planet. Wouldn't it run out of electrical power when travelling between stars for thousands of years? there wouldn't be any solar power that could be captured because you're too far away from the stars, radioactive sources would decay over time, chemical batteries would probably slowly decay too.
It's not like we're going to be able to move a heavy space ship much faster than voyager.

Unrealistic fantasies that some day we'll be able to live on other planets anyway is leading to complacency about the state of our own planet which is the only planet humans are ever going to live on.

shouldn't more responsible scientists say that travelling to and living on other planets is childish nonsense?