Going from jquery to angular was a world of change. But it was relatively simple and fun to write SPAs. But then webpack and react came along... those two are among the most complex JS projects I know of.
Their internal code is nowhere near clean and the concepts neither. They generate immense webpages that are shiny and all but it's such a large mishmash and keeping track of state with the state manager is horrible.
Also debugging those two projects... Both have convinced me to step away from JS. It's just too much complexity.