They are often sold as "fairly lights" online. This is just one use where the manufacturer used them in a different way. They look fragile but are remarkably strong. Yes, they are non-replaceable but since they are LED, not incandescent should last a long time.
I bought a few battery operated 20 LEDs for a friend to use as lights in a bottle for less than a dollar each. I have a few sets of 12V lights. They are so flexible that I was able to string them on one of those old circular trees that lie flat when stored and mount on a tent pole in the center. You can buy them in USB 5V DC, 12V DC , or operated from a battery pack. I just looked up current prices and I can find them in 10m 100 light sets for under $2 and 200 light sets for around $5 from China