This was the question in the article. They did a test of unwashed, washed 3 times, and washed 10 times, then compared the rice. The scientists found no difference between the samples. They further speculate that the stickyness level of the rice has to do with the starches that leech from inside the rice.
The article goes on to talk about how, depending on how (and where) the rice is processed, you may want to rinse rice to remove bits of husk, dust, pebbles, and possibly arsenic or microplastics.
Now, having said all of that, take the results of the study with a grain of salt. Washing 3 times isn’t going to do much of anything, and 10 times doesn’t actually tell us that they washed the rice properly. As soon as the starch is wet, it’s sticky. You really have to rinse and agitate the rice, and wash until the water runs clear. Maybe that also leeches some of the more available starch from inside the rice, but the difference is noticeable to anyone who cooks rice on a regular basis. So I’m not going to question the suggested mechanism of action, but I know how to make rice that is and isn’t sticky.