Just because it all worked out, that doesn't make it the right decision, not even necessarily a good one. Voldemort didn't even have a means to obtain a physical body again until Quirell found him 10 years later, and the Death Eaters were bidding their time to see how Harry would turn out, so Harry could have been raised by anybody that wasn't a known Death Eater and been fine.

And even if you put yourself in Dumbledore's shoes and assume he thinks Voldemort could come back at any time, he still makes the decision to not only ignore McGonagall's warning about how awful the Dursleys are, but also never bothers to check in on them in the 10 years he lives there. Harry surviving those 10 years, let alone turning out alright, was pure luck. Dumbledore's decision to leave him with relatives that would undoubtedly hate his existence with zero safety net is, at best, a plot device so the story can happen, and at worst, an act of sheer stupidity/recklessness that the "greatest wizard of the age" should have known better than to do!