Could you hack this together on your own? Sure! If your time is worth nothing.
Massive timesaver, clean code, only recommendation would be using github - but maybe the maker is preparing a course and sells that on top. ;)

All in all: I like what I see. There is no much news in it but as mentioned, its a massive time saver and much cleaner than any of my own templats.

Wishlist: (and happy to pay extra if you keep that quality up)
1. Use Github (also for updates...?)
2. Consider sharing some weird stuff (how to make your own omnibar style overlay to search in bookmarks, history, ... )
3. Crossplattform exports (at a minimum .zip for chromium based browsers such as edge and chrome)