The thing nobody tells you is that most outdoor stools and benches look fine sitting empty in a store and then feel completely wrong the second you put a drink, a plate and a pair of elbows anywhere near them. A bench that's too narrow turns dinner into a balancing act. A stool that's too tall for the table next to it means someone's eating with their chin level with their plate. None of that stops me from wanting them everywhere, because nothing else solves the problem of extra seating that can live outside, take weather, and not demand its own closet.
These earn their spot on a small patio, a fire escape, a strip of balcony, a backyard that only gets used three months a year before the rain moves in. A single stool tucked by the door for shoes and plant pots works in almost any space, even a fourth floor walkup with no yard at all. Benches ask for more commitment, they want a porch or a deck where people are actually going to sit for longer than five minutes, and footstools are the quiet luxury item, the thing you don't notice until you're putting your feet up on one on a warm evening and wondering why you waited so long.
Measuring matters more outside than in, mostly because the margin for error is smaller. A bench under four feet long seats two people if they like each other a lot. Anywhere over five feet starts eating into a space you need for walking around a grill or opening a door. Leave at least two feet of clearance in front of any seat for legs and for someone to actually get up without doing a weird sideways shuffle. Stools should sit a few inches below whatever table they're paired with, and I've learned the hard way that "it looked proportional in the photo" is not a measurement. Measure your actual doorway too, some of these are heavier and wider than they look once assembled.
Where they fall apart is anywhere with real storage limits or harsh winters and no shed. A bench you can't move easily becomes a planter stand covered in snow by December. If your space is tiny and uncovered, a stackable stool beats a bench every time, since you'll actually bring it in. Measure the width of your door or gate before you buy anything that doesn't fold flat, because getting it home is only half the problem.