Well, even if we could not reach such a planet in a reasonable time yet, a research like this could still be very useful for many reasons.

It could help us learn how our habitable environment works and operates, it might be applicable for terraforming or habitat construction.

There is also a non-zero chance of some sort of life, possibly intelligent developing in such an environment (as proven by our sample size of 1). That life can be active at the moment (from our PoV - light speed and all) or was active in the past, so we should look for bio signatures or even signs of mega scale engineering.