why don't the devs work with the creator of this alternative site and make it the official site?
For a reason that only people who have deep technical understanding might understand, or people who come from an IT security background: Technical correctness. It's a value in itself. Technical correctness and cleanness is more important than having bells and whistles. Javascript is
not good. It's running other peoples code on your computer, without asking what it does. HTML is a markup language, not designed for interaction. And most importantly, presenting information, like a homepage intends, does not require interaction! It can be static, reducing the overall complexity and maintenance effort.
Furthermore, reducing the sites complexity also reduces the size of the website, which will be relevant for people who don't have such a high-speed internet connection, who are also part of our target audience. Tor Browser with high security settings blocks Javascript by default as well, which breaks the "alternative" site.
JBG is a high quality dev and he understands the importance of correctness when writing software. The goal of this project is to be of high quality, to provide the
best technical solution. That's also how the Tor integration was built. Having a simple, static website that focuses on the content is more important than having a site that looks flashy, but at the price of unnecessary complexity.
So to me, it leaves a very good impression. It looks competent and clean. 100% perfect!