Did I miss a privately funded, reusable heavy lift rocket coming out of old space in the past 20 years?

I guess it depends on which decade you look at. The Saturn and Shuttle programmes achieved more novelty for the time on faster timelines. Of course, they also cost a lot more....

That is clearly not true. SLS is much more expensive by any measure and is not reusable in any way. Other interesting work, e.g. rocket lab, is not old space.