"Practical" is a strange word to use for something that might well be akin to a taxonomy of unicorns.

Consider simply the idea of becoming interplanetary. Establishing a colony on Mars would cost quadrillions and take generations, and we would end up with people living in a dark, freezing cold, arid, lifeless, airless, poisonous, radioactive desert periodically swept by devastating storms of abrasive, static charged dust.

Who would want that? Antarctica is better in every single way, and yet no one actually lives there.

And colonizing planets around other stars would be many orders of magnitude more costly and time-consuming than that.

If we as human beings can't get it together to spend the trillions and decades it would take to not kill the one biosphere we know about, how would we possibly keep it together to spend the quintillions and centuries it would take to colonize the galaxy?

There's a good reason why almost all interstellar SF stories start off with some magical technology that allows people to simply "jump" to some other star system. But we've had more than a century of relativity and there's just zero evidence that it isn't true.

It is very likely that the stars are not for us.