I don’t even have some fairly close friends on FB!

With Snapchat I don't see such trend. It has no website, only a confusing mobile app with horrid UX that most people can't figure out and is mostly used for adding pig noses and cat ears to pictures by teenagers.

The whole point of Facebook is to "record personal history".

The whole point of Snapchat is to maintain "privacy". It fills a void that Facebook was never meant to do nor intends.

Before someone says "you can still screenshot" on Snapchat. While that is true, the platform strongly discourages it and millions of users do not screenshot for every single photo. Whereas FB, is default "save"

The way a platform facilitates interaction is very important.

Sending pictures that disappear and are not recorded is a valid use case but it's a very narrow one in my opinion. It might be useful for dating or "flirting" conversations so maybe 10% of human interaction.

Therefor I think the way Snapchat works it will never become mainstream like Facebook did because it doesn't work well for normal interaction between friends & family which is 90% of most peoples' social interaction.

Snapchat is already mainstream, it has 178 million daily active users. Tons of celebrities use it too. It's not some unknown app. Facebook is still more popular by a large margin. However, that doesn't deny Snapchat being labeled "mainstream".

>I think people want to keep personal history in most cases. Like all normal conversations with friends or family, you would want to keep history of it so you can go look up things in the future.

Again, Facebook and Snapchat are two different apps. Snapchat was never meant to become a Facebook copy-cat. They both fulfill two different purposes.

Your comment is similar to watching a horror film and complaining that it wasn't a comedy film and explaining how horror films do poorly compared to comedies. They are not mutually exclusive.