Part of the reason for it being a tallboy is that aluminum cans are more recyclable than water bottles, potentially infinitely so, while water bottles either have a limited amount of recyclability potential or aren't actually recyclable at all.

The other reason is to literally make it more fun and appealing to drink something other than alcohol at concert venues. Part of getting over addiction or even getting away from a culture that is doing you harm is, in the US at least, heavily associated with becoming "no fun". The idea here is to make water as fun in terms of packaging as alcohol, so people who are going sober, who can't drink, or who are the Designated Driver don't have to feel like they're relegated to the "no fun zone" forever and still get to order something with a silly name. We had these at my brother's wedding as an alcohol alternative and tbh it was really neat.

From the Liquid Death website:

"Most products in the health and wellness space are all marketed with “aspirational” fitness models and airbrushed celebrities. And many of us are tired of it. Why should unhealthy products be the only brands with “permission” to be loud, fun, and weird? And let's be honest, almost all marketing and branding is just theater. So we’re going to treat our theater like a movie theater and have more fun with it."

on the bright side i am not addicted to crack cocaine