Javascript was never explicitly designed to use one thread: it used one thread because Netscape used one thread. This is back in the 1990s when multicore on the

Javascript was never explicitly designed to use one thread: it used one thread because Netscape used one thread. This is back in the 1990s when multicore on the desktop didn't exist and JS execution speed was a non issue. The page you linked to shows a full and complete library of concurrency tools, which you don't have to use if you don't want to. How is this evidence of being worse?