It depends.
Everything fitness related has a 'you can do it yourself for free' alternative. Fitbits, gym visits, slimming clubs are all examples where people pay, for a variety of reasons, to help them reach a goal.
If you're losing weight anyway on your own, then probably not.
If you enjoy a bit of online encouragement, like hitting targets, want a measure of how much better/worse you are doing, want to share your activities with family/friends and be encouraged by them too, then it will probably help.
I have a Blaze and the Aria scales, have worn a Fitbit for a few years now, and I love it.