That's a good point, especially the part about the rating. When we saw the fires here that time, we saw a lot of safes that didn't make it. We only work 2 miles from home so I have always assumed we'd be able to run home and grab stuff, but it's not like we take all of that stuff (except passports) with us when we travel. I'm going to look into it; I appreciate the suggestion.
There are quite a few different safe ratings, so it's worth doing some reading about what you want to try and protect.
Another big problem with many safes is that they're, well, heavy. And heavy things don't hold up well in a fire, because they tend to fall. And that breaks things or bends things well enough to allow smoke and flame ingress. Or, let water in after coming down (because things that were on fire often end up very, very wet afterwards).
Most of the document safes are designed for that - they're designed to take some physical abuse, though I wouldn't store them on the second story, and they seal up to be water tight in a fire.
And, if you're looking at wildfires, it's worth considering that there may be zero firefighting - so you've got a different thermal environment from a typical suburban structure, where the fire crews will be on site quickly cooling things down. If you're looking for something that can keep documents intact as the whole structure burns, and then can survive a few days sitting in the (hot) ashes, you're looking at more expensive unit than the cheapest fire safes out there.
Though I'd put more time and effort into defensible zones and firebreaks and such. I need to get my tractor running again because my current method of cutting fire breaks (string trimmer) did not hold up well against the grass fire coming through. Mostly because it's enough of a pain to cut large breaks with that I didn't defend well against a fire coming downhill at our property... (I'd guarded against stuff coming from the road and coming uphill, but this particular one came hauling ass downhill). So I'm going to disc breaks next year and deal with the dust.
I would be reluctant to try and talk anyone into preparing for every disaster: you'd end up with even more crap to protect your crap!
Fundamentally, there are two things you need to prepare for - almost everything else is a special case of those. Bug-in, and bug-out.
Bug-in is where you're staying in your house/on your property, and you'd better be prepared to do so without services (water, electric, gas, depending on your environment). So consider lighting, cooking, and basic thermal management (cooling probably doesn't matter, but if it's -10F out, you may want a way to heat). One perk here, if you're into camping, is that camping supplies make for perfectly good emergency supplies in most cases - our backup cooking plan is our camp stove, and I have adapters to fill the little 1lb bottles from bigger propane tanks. I don't have a way to run our well pump without grid power right now, but we store a bit of water for that (and I'll eventually have the transfer switch and generator installed, and/or off grid capable solar wired in or routed from my office). Consider food as well - if you've got a big freezer, it's fine for a while without power, but you'd better be able to either power it or keep stuff frozen (backup plan in the winter is to simply put the contents outside in the shade when it's below freezing).
For bug-out, you want to be able to grab what you need and get out with limited time. A document safe is helpful here (and a good reason for having a separate document safe from a general safe - I can grab and go with the document safe in a hurry). And some bags or backpacks or such. Also, depending on your vehicles, you can keep some stuff in them - I normally keep a decent selection of supplies in my truck, though they're out right now because I was hauling a bunch of shed remains in my bed. But "emergency road gear" for getting stuck on travel is useful as bug-out gear as well. MREs are worth tossing in as well, some water... you can get a good distance on that.
There's no particular reason to go "prepper overboard," and a lot of that stuff isn't particularly useful anyway, but being able to take care of your family for a week or so grid-down and standalone is a good idea for pretty much everyone.