They work fine, but they do not tolerate direct heat. So, if you are steeping, shut the heat off & wait five minutes to put the bag in. When you take it out, get something under the bag to support it before removing it from the water.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk