Let me show you some of the main points that why node.js is trending in modern web development era.
Node.js is well supported by major tech giants. Google backed angular, Facebook created React. Amazon Lambda supports Node.js. Microsoft's most famous developers favourite VSCODE is built on nodejs framework electron.
Node.js is very easy even for beginners. It is easy to setup and running your servers in no time. It does not require a specific apache or nginx server to be used.
Less development cost. You can have your full stack app built by a single developer. MEAN, MERN and VENM stacks are currenlty in very high demand. There are many developers available who can develop your backend for you, manage your database and also develop you frontend too. All with same language from front to back. No need to spend money on multiple developers.
Node.js can handle almost double requests per minute than PHP or Python. Real Time web apps the main thing where node.js shines. Handles heavy load on real time connections smoothly than PHP or Python. Far better scalable than PHP or Python.
Node.js is always under active development. They also release LTS (Long Term Supported) version every two year. It has mature enough web framework like express. Express project is under Linux Foundation so it is under best in class development community.