Depends on the camera and other such features. But you're right that it's not a given.
> often wrong timestamps
I'm confused by this. I suppose if you leave your camera off for years at a time, have dead batteries and don't bother checking it - then sure. But in general the RTC on cameras is very good and not an issue. Even if it clock drifts by a minute or two, does it really make a difference?
> slow startup time
Incorrect with modern cameras. If I have both my Nikon in my hand and my phone - I can take a picture with the Nikon WAY faster and more reliable than my iPhone. The Nikon can go from off to taking a picture in half a second. The phone you need to press the camera button on the lock screen for a full second before the camera app even launches. Then it takes it a little time to launch the app and warm up the camera.
Are either slow or problematic? No. But the Nikon is way more reliable, sometimes the iphone just derps out.
> useless tiny batteries
Again, I suppose it depends on the camera. My Nikon is rated for a thousand shots a battery, I think? Even my smallest and oldest handheld is rated for 300 shots a battery. Unless you're going way crazy, that is a lot of photos in a single day. It'd run down your iPhone quite significantly as well.
One area that is a big difference overall... Video.
Slow startup times really shouldn’t be an issue in this decade. This is something that was an issue maybe in the early 2000s.
You will generally be able to turn on the camera more quickly than you can navigate to the camera app. (Physical switch plus sub one second time to turn on).
On Android phones (maybe iphones too? no clue on that) you can set a double-press of the power button to launch any app you want, so if you turn it to open the camera then you can launch directly into the camera without even needing to unlock the phone.
Doesn’t matter. That‘s just equivalent to the physical switch in time needed (maybe even slower, a double press does require more dexterity) and startup times on phone cameras certainly aren’t faster than dedicated cameras. My iPhone 12 Pro takes about a half second to a second until it‘s ready to take a shot.
My mirrorless camera isn't new, but not early 2000s either (GX1, released 2012). It takes about 10 seconds to first photo from off. My Android phone can take pictures without unlocking it, and I've repurposed the PTT button to open the camera app. I can take my phone out of my pocket, take a picture, and put it back in my pocket faster than my camera can turn on.
Yeah, navigating to the camera app doesn’t take long. But flipping a physical switch also doesn’t and startup times of both after the switch is flipped / app is started are about equal.
So: with my EVIL camera I also can be taking a photo about as fast as I can raise the camera.
A camera is far faster in "startup time" (there's nothing to start up, just press the shutter to take a photo). And a DSLR will outlast battery life of a phone at least 100x.
No, the DSLRs can be left permanently on. It consumes nearly no battery in that state (a single charge will last many months) and yet it's always ready to take a photo as fast as you can grab it.
Weird.
This, combined with the lack of geo tags, often wrong timestamps, slow startup time, and useless tiny batteries, I use my camera rarely.