People who get mad at this episode because "That's not how evolution works!" miss the point of Star Trek.
Chronotons and dilithium crystals also don't exist. The science of Star Trek only exists to facilitate interesting stories, involving character drama and philosophical quandaries.
It's just bad writing. They could literally all come back to earth, get the same injection Tom and Janeway had and in a couple of days they would be back to Earth. That is without considering that warp 10 was a side project of a lone helmmen stranted on the other side of the galaxy, just think what the best federation scientists would do with the appropriate reaources, in a couple of years they would eliminate any adverse effect.
You can't just drop one of the most relevant scientific breakthrough of the century as a story for a single episode and then completely forget about it.
Tom Paris was able to build this in the Delta Quadrant! With a box of scraps!
