I don't think the OP plans to carry around the passport on a daily basis just for fun. What is meant is a passport envelop wallet for traveling. I have long debated whether such a thing was useful. I am still not quite sure.
Well I have 2 passports and a number of cards I travel when travelling only - my foreign ID card, driver's license, boating license, some extra credit cards, SIM cards, etc. I currently have a LL Bean organizer where I store all of those but it is rather long and large (about 9 inches in length) and would like to replace it with something smaller and more compact that I can fit in a sport coat pocket when traveling. I find it necessary as it holds items other than those I carry in my pocket on a day to day basis.
It is nice but I need one for 2 passports, ID cards, etc.