True, but they are substantially bulkier. Volume and total weight for a bugout come into play. If all you seek is to get home safely over XX miles and Y days, then you may not need military poncho(s) in your get home kit.
As a test, take a 3 mile hike around your neighborhood wearing your backpack with weights in it equal to your total load out. Wear the shoes you keep in the vehicle.
That may open your eyes. Especially if you try that hike ALSO carrying a couple gallons of water.
I wrote GALLONS, I meant QUARTS
I’ve backpacked for years, and still hike a lot; I have no misconceptions about weight. They are heavier/bulkier, but those $1 “emergency ponchos” aren’t durable at all in brush - and some come in colors that make you REALLY stand out (which makes them handy for a glove box - if you’re changing a tire on a rainy night you want to be visible). Also, the cord inside lets you fit it better.
They fit well in the Molle II waist pack, which attaches perfectly to the bottom of the Molle II assault pack - which is an ideal bug-out bag.
Just my $.02; there is no “one-size-fits-all” bug-out bag due to each person’s particular area/circumstances.
As a test, take a 3 mile hike around your neighborhood wearing your backpack with weights in it equal to your total load out.