We know we're better than this, but we can't prove it--Tony Gwynn
Nothing is perfect in every situation. The best you can do is good for the time being.
Someone asked me about ponchos. I've used them. At times, wonderful.
But if you get out there above tree line, say on the Colorado Trail, and it starts to storm, you gotta make a decision.
Keep low, with the pack which also has metal tent stakes and a cook set. Or ditch the pack, lay low and wait it out.
If the poncho is a pack cover, rain jacket, shelter combo, something's gotta give.
On my trail testing experience, the pack ended up with a black plastic bag to cover it, while I hunkered down under the poncho a few hundred feet away. Lighting does kill people, and it was striking the nearby trail.
Pre Plastic Bag find, I had to sit it out with the poncho protecting me and my pack. Thankfully, I do have a light pack, albeit, sometimes stuffed with a week's worth of food.
As a sewer and designer of trail gear, finding myself about 10,000 feet with a pack protected with a garbage bag was truly humbling.
I'm better than this!
Well, I can be.
That time I pushed the envelope.