Nothing that uses fossil fuels is “good” for the environment. But my log burner isn’t for decoration, it’s for heat. It’s hard work cutting logs, splitting them, moving them somewhere dry for a couple years, then moving them somewhere easy-to-get-to when they’re ready to burn. I like having the stove, but don’t light it for its aesthetic effect. I also like the whole process of managing a small patch of woodland. I see that as more sustainable than our oil central heating.
I agree that smoke and particulates they release cannot be good for health. I see them as yet another unhealthy thing I willingly expose myself to - like red wine, bacon, red meat, sugar, additives, etc etc. The impact to others is tiny - I live rurally so the only people who are unwillingly exposed are people driving past (typically in deisel 4wd!), so they’d have tiny exposure levels.