Webdev isn't complicated. Its actually pretty simple. Because its simple, you can use the extra time you saved to solve complicated problems. Which then brings it back up. When the platform makes THOSE problems simple, you just move on to solve other more complicated problems.
Basically, developers can support complexity . No matter what you do to simplify it, you'll always push toward , just getting more value out in the process. If you don't, your competitors will.
Also, even the most complex rollup/webpack/react/redux/styled-component/npm/blah/blah/blah setup has nothing on the kubernetes/kafka/databases/queues/whatever infrastructures of the world.
It just turns out that while your little pet project that cuts every corners to get something working has little on software development that requires everything to line up, be fast, reliable, comply with all the laws and regulations, and scale once your company grows and you suddenly have hundreds or thousands of people that need to work on the same stuff.
One thing to add: some people actually like setting stuff and optimizing infrastructure, build processes, setup, and pushing it to its limits. So development stacks quickly get optimized for a very common way to staff organizations: have a team that handles all the setup and infra, and a bunch of teams that build on top. So when you try to have 1 person or 1 team do everything, it feels like too much.