"Blind Bag" toys and collectables are actually quite common. A web or Amazon search returns an abundance of such products which range from different IPs (Video games, tv shows, etcetera..)

There are also YouTube channels devoted to opening these products in bulk.

Pokemon cards, baseball cards, hell, even these subscription box services that are popular nowadays could be considered 'real life loot boxes'. The idea of a product that you purchase not knowing it's contents is not new idea, but it seems like we have decided that loot boxes in games are different from these products.

Using Signal isn't all that inconvenient, it's just not a pretty app. It does what it advertises, it sends messages, photos, voice memos with a few extras like disappearing messages. Sure, it's missing the 'frilly' features like Samsung and Apple have in their messengers but it gets it's job done considerably well. I think Signal is actually a better example of an application where the privacy/convenience trade off is rather mild. There are no requirements to authenticate each time you open it, you can choose weather or not to allow in-app screenshots, it still sends SMS (on Android) so it can replace your built in SMS without having to switch between secure and non-secure apps for messaging.