Lisi's work is generally considered extremely unlikely by physicists. The eye-catching title and colorfulness of its author attracts a lot of attention with the public, but it doesn't match experiment. It has basically been abandoned.

I agree that we could probably spend billions of dollars better than on another enormous collider, even within high-energy physics, but it probably wouldn't be best spent on E8 Theory. Figuring out how it would be best spent, however, would be contentious to say the least.