I've always found this whole topic so intriguing because I always thought there was one option.
My wife and I started dating when I was 16 (now 41) so we've been together 25 years this November and just had our 19th anniversary on Monday. During that time, it just seemed like the only thing to do was make what was mine, ours, and everything of her's, ours. We never even had a conversation about it, I guess we just figured that was part of marriage - 2 becoming 1 so to speak.
Now, we obviously have our own things to an extent - i.e. we have our own computers, headphones, and even bedrooms (I snored horribly prior to CPAP), but it all comes out of the same (shallow) pool of money. There isn't money that is mine vs hers or spending that I cover or she covers.
Always incredibly intrigued by the separate accounts and bills/spending. My personal perspective was it seemed like a lack of full commitment to each other... but I no longer think that based on the sheer volume that do that model.