React, just like most software today, is excessively complex for the tasks it performs.
The only reason React is used is that many use it as a framework to attempt to provide more interactivity on the page without page reloads. There are other frameworks to do this, but none are as well-used.
Webpage interactivity with data was accomplished with page reloads via cgi-bin in the 1990s. Everything that has been done since then was not strictly necessary to produce the websites we use today; it would just be a more choppy experience.
A smoother experience didn’t require the overwhelming complexity that was introduced primarily in the 2010s in a framework war that React basically won. That complexity is the reason why many web and full-stack developers in the 2010s (such as myself) lost their minds and quit or seem incredibly depressed, grumpy, and confused much of the time today, and why some have invented strange new frameworks to attempt to reduce this complexity.