Aluminum works good, we've had a set for a couple years. It's a black all aluminum finish, looks like wrought iron, no marks or evidence of weathering at all on the table or chairs. We thought about getting one of the ones with tiles, but since the tiles can break easily we went with the all aluminum.

What about rusting and fading?
I had a set a few years ago that was black and shiny when new, but faded badly after just a couple years in the sun and was showing signs of rust. It would have cost more to repaint than the value of it, so it was disposed of.
I don't think I want anything else that is painted where the paint can fade or peel off with age and exposure to weather,
What is on that patio furniture in the photo that gives it that dark color?

I have seen some patio furniture in the outdoor seating area of a nearby restaurant looked as if it was made out of stainless steel and looked pretty nice, Their patio was pretty well shaded though.
However, I have some stainless steel cookware that has been through the dishwasher a few hundred times and still looks great. If the material can handle the harsh dish washing detergent chemicals, I would think it should be able to handle sun and rain.

Steel rusts. Aluminum doesn't, but anything can fade. Much of the aluminum outdoor furniture sold here is made in China, and they are not so concerned about junk they have mixed in with their aluminum. Sometimes the joints on their furniture fail.

You couldn't leave your car out day and night for years and not expect it to fade or rust. You have to use and maintain some type of protection over the powder coat paint finish that most aluminum patio furniture has to make it last longer.

As for mesh slings, if you check the fine print, they are only warrantied for a certain number of years.

Here is a link that might be useful: Brown Jordan Furniture

Actually, in this area cars can be parked outside for years without fading very much and have no rusting. There are no deicing chemicals used around here and rust is rare on cars.
They won't look good "forever," but there are plenty of ungaraged 10 year old cars that are outside 24/7 and still look very decent and can still go several more years before they look like they need a paint job.
I'm looking for furniture that will hold up well for at least that long. A little bit of fading will be OK.
Maybe some good quality aluminum furniture is what I need to find.

The person who posted the photo is not saying what that set is, but I Googled the photo and came up with this at the link below.

It is also on the Lowes web site.

Here is a link that might be useful: Darlee Nassau 4 Person Cast Aluminum Patio 36'' Square Table Dining Set Antique Bronze

Jaxo, thank you. I also found it on another site after Googling Cast Aluminum patio furniture.

I do wonder, though, how it keeps from absorbing heat and not being uncomfortable, or even burning, hot to sit on. Anyone know?

What about commercial patio furniture like restaurants use in their outdoor seating areas?
Maybe that will built to be a bit more hardy against weather exposure..
Is there a good place to buy that type of patio furniture?
I might go that route if I can find some that looks good and doesn't appear to be "obviously" commercial furniture.