I've seen this browser pop up occasionally and I still don't understand a single thing about why it exists. The only thing I know is that they really, really, really, really love Apple. Their FAQ says:

In other words, Arc is to your ex-browser what the iPhone was to cellphones. Or as one of our members said “like moving from a PC to a Mac.” It’s from the future — and just feels great.

Yeah pffft, imagine using an Android phone in current year. We're like Apple so much that we also throw a bunch of buzzwords instead of explaining the product.

Also their #1 selling point is privacy and how they'll never sell your data but uh... Firefox exists... And it's open source, unlike this...