"Just"? We have a wood stove. We primarily heat with it. It's awesome, and I don't want anybody to think otherwise with what I'm about to say.

It'll keep the place above 50F/10C starting from 62F/16C unattended for (generously) 8 hours. Less if it's cold. Is this primarily because the house is a log cabin with 50 year-old windows? Yeah, but lots of other houses are poorly insulated too. Once it hits 50F, a direct vent propane furnace kicks on to maintain that temperature.

When you are around, it requires a certain amount of active participation that a regular furnace does not. Is it burdensome? No, but it behooves you to have a look and act every time you walk by if action is needed.

It heats one room well, and the rest of the first floor poorly. We've added a 200mm case fan to circulate some air from the living room (where the stove is) to the kitchen. The kitchen will be a reasonable temperature several hours after the living room nonetheless. This is a roughly 600sf/60sm first floor. The second floor stays decidedly brisk, which is fine because we like sleeping with it cold. Obviously the circulation fan isn't running when the power is out.

It takes up a bunch of space. Wood stoves require clearances for safety: You don't want to light the wall on fire because the stove is too close. And probably also a non-flammable hearth for many applications.

The chimney needs an annual cleaning. You could argue that a rarely used chimney doesn't need to be cleaned of creosote on an annual basis, but the chimney sweep is also doing inspection of everything and making sure e.g. the cap is still attached and doing its job of keeping the birds out. I would not be excited by the idea of a whole subdivision worth of suburbanites lighting their wood stoves simultaneously for the first time in 5 years at some remove from their last chimney inspection.

The exhaust is likely dirtier than a modern gas furnace. Especially while you're getting it going or have it damped down. There are EPA standards, sure, but there are a lot of old stoves out there that don't comply.

Wood. We burn a couple cords annually, typically 2-ish. That's on the low side, in part because our wood stove is a little undersized (we didn't buy it), and you'd be hard-pressed to burn more in it if you tried. If you're only using your stove for an emergency, you surely don't need that much, but remember, we're really only heating 1200sf. Most houses in the US are somewhat larger to obscenely larger. A quarter of a cord isn't likely to last long in a cold snap with the power out. How much wood are we asking people to keep around for a (hopefully) once every five year occurence. Plus kindling. Plus tinder. Plus matches.

A wood stove is like any other mechanical system. It works best when it's well-maintained and the user is well-practiced. It takes up an immense amount of space inside and out that's hard to justify paying for if you aren't using regularly, and it does an inferior job of heating a typical-size US house at best.

Fireplaces, dare I say, are worse in literally every respect.

We did not lose power the weekend before Christmas; we got nailed the weekend before. It was lovely; it was like a vacation put a stockpot on top to melt snow for water (the well pump doesn't run when the power is out).

On the other hand, I missed my nephew's birthday because one of us had to keep the house warm. I also ate box mac n'cheese for a couple of meals. A wood stove that isn't specifically designed for cooking doesn't cook, and an electric stove isn't worth a shit when the power is out. Fortunately, we're hikers and have a backpacking stove. Unfortunately, it doesn't lend itself to particularly fancy cooking unless you've planned very specifically to cook on it.