In today's complicated web application ecosystem, starting a system from scratch is some seriously hard work. There's an incredible number of choices to make in terms of frameworks, JS language versions, build processes, back end integration, etc. And once you choose these things, you have to piece them together.
Fortunately, there's a number of different starter "seed" projects out on GitHub that provide pre-packaged solutions with much of this work already done. You can generally find something that's using the combination of things you're looking for, in a state that is more or less ready to go. But, while they provide everything you need for front end, they typically don't provide much in the way of back end integration. You'll see them using mocked services with files containing JSON responses, or sometimes calling 3rd party APIs. So when developers want to start incorporating their own back end, they still have some work to do. And, I think not coincidentally, you will often see questions on sites like StackOverflow regarding issues with this process.