Is snapchat accessible with voiceover and do you think that there's a reason for a blind person to use it?
If you take a minute or too to figure out how it all works, it's at least usable. I typically only use the messaging functions myself and see what friends are up to. Whether or not you think it's worth using comes down to personal preference really. I could go months without using it if I'm being honest, so yeah to each their own.
There are good reasons to use Snapchat if you can capture an audience within the 10 second timeframe. Make your video content compelling, and you will generate a following.
From my experience, Snapchat is somewhat accessible. But I rarely used it because so many of my friends, even sighted ones, don't use it, or even if they do, they at least use Line, FB Messenger, Skype or Whatsapp alongside.