Your are mixing up eras. For comparison: when Javascript was first designed, performance wasn't a goal. Later on, people who had performance as a goal worked

Your are mixing up eras. For comparison: when Javascript was first designed, performance wasn't a goal. Later on, people who had performance as a goal worked on Javascript implementations. Thanks to heroic efforts, nowadays Javascript is one of the language with decently fast implementation around. The base design of the language hasn't changed much (though how people use it might have changed a bit). Python could do something similar.