So I think Snapchat provides the "moment" experience in 2 ways.

1. When you are with people, like at a concert, the spontaneous authenticity of the platform encourages you to just take a quick video or photo and then put the phone away so you don't get 'lost' in the app spending time adding filters, stickers, prettified text etc (ala Instagram, Snap also has these but feel more lightweight to me) and instead get back to the real life.

2. The people receiving these snaps get a more authentic version of you and your experience so are maybe more connected to your moment.

I agree with your point though that it can still be used in a way that is unauthentic and distracting from the moment (now instead of just living and experiencing whatever is happening I think 'oh I should share this on Snapchat') but I suppose why I like it vs other tools is that for me it encourages the more positive direction although not perfect.

i was at a concert last night with my 14 year old daughter... every kid had their phones out the entire time and was constantly snap chatting/IG story-ifying everything and there were spending more time trying to impress people that weren't there than they were actually spending time enjoying the show...

oh, snapchatting them smoking or vaping.. IG'ing the band. apparently its just cool to show how they're breaking the rules on snapchat and then bragging about being at a show on ig...

luckily my daughter just laughed it off... but she did IG a few songs so /shrug